- Email: [email protected]
Ambient processed CsPbX3 perovskite cubes for photocatalysis
Journal Pre-proofs Ambient Processed CsPbX3 Perovskite Cubes for Photocatalysis Sayantani Das, Tufan Paul, Soumen Maiti, Kalyan Kumar Chattopadhyay PII: DOI: Reference:
S0167-577X(20)30206-8 https://doi.org/10.1016/j.matlet.2020.127501 MLBLUE 127501
To appear in:
Materials Letters
Received Date: Revised Date: Accepted Date:
16 December 2019 12 February 2020 13 February 2020
Please cite this article as: S. Das, T. Paul, S. Maiti, K. Kumar Chattopadhyay, Ambient Processed CsPbX3 Perovskite Cubes for Photocatalysis, Materials Letters (2020), doi: https://doi.org/10.1016/j.matlet.2020.127501
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
© 2020 Published by Elsevier B.V.
Ambient Processed CsPbX3 Perovskite Cubes for Photocatalysis Sayantani Das1, Tufan Paul2, Soumen Maiti3, Kalyan Kumar Chattopadhyay1,2, * 1Department 2School
of Physics, Jadavpur University, Kolkata 700032, Jadavpur.
of Materials Science and Nanotechnology, Jadavpur University, Kolkata 700032, Jadavpur. 3St.
Thomas College of Engineering & Technology, Kolkata 700023, India *Corresponding author email: [email protected]
Abstract All-inorganic cesium lead halide (CsPbX3, X= Cl, Br or I) perovskite cubes have been prepared by low-cost solution-based technique at room temperature. As synthesized perovskites were characterised by XRD, FESEM, TEM and FTIR. Photocatalytic activity of the as-synthesized cubes was investigated taking hazardous Eosin-B dye as model contaminants. Among all the synthesised samples CsPbCl3 cubes showed superior catalytic performance and degraded the dye solution within 140 minutes under visible light. Going beyond well reported catalytic study on CsPbX3 quantum dots, this study not only establishes the potential of CsPbX3 cubes in dye degradation also provides new insight on the impact of morphology on it.
Keywords: X-ray techniques, FTIR, Electron microscopy 1. Introduction: Recently, organic-inorganic hybrid perovskites have truncated a considerable attention both from academia and industrial field due to their low-cost solution processing, tunable bandgap, long diffusion length, high charge carrier mobility and large absorption coefficients [1, 2]. All inorganic perovskites with chemical formula ABX3 are generally stable in orthorhombic crystal structure at room temperature, where A and B stand for two cations with dissimilar sizes (generally A = Rb+ or Cs+ and B = Sn+ or Pb+) and X denotes for anion
1
(halides: X = F-, Cl-, Br-and I-). All inorganic CsPbX3 possess several unique features like ultra-high photoluminescence quantum yield, excellent stability, narrow band emission etc. [3, 4]. Textile effluents from industrial waste has polluted the water and make it unfit for consumption [5,6]. Such sewage contaminated water is carcinogenic and poses serious threat to human health. Degradation and conversion of these hazardous contaminants into harmless one is essential. Numerous strategies have been adopted for wastewater purification, among which heterogeneous catalysis under light is widely accepted due to its high efficiency, non-selectivity and cost effectiveness [7]. Photocatalysis employing transition metal oxides is well presented in literature [7]. However, exploration of aforesaid using all inorganic halide perovskites is still lacking. Though there are few reports on photocatalysis by all inorganic halide perovskites however most of them based on quantum dots [8, 9]. Here, adopting a facile, budgetary approach we have realized CsPbX3 cubes. Only changes in halide reagent in similar synthesis protocol lead to different cesium lead halide cubes. We have examined the catalytic behaviour of CsPbX3 cubes using Eosin-B under visible light. Registered results suggest variance in catalytic performance and highest efficiency of CsPbCl3 cube as compare to others. Being not restricted to quantum dot, photocatalytic analysis of these CsPbX3 cubes will provide a new insight on the impact of catalyst geometry on photocatalysis.
2.1 Experimental For the synthesis of CsPbBr3, initially PbBr2 (0.36 mg) was dissolved in 2 ml DMF. An oil phase was prepared by adding hexane (10 ml) to oleic acid (1.0 ml) and n-octylamine (0.25 ml). After that CsBr (0.21 mg) was added slowly into the PbBr2 solution and the final solution was mixed into the oil phase under vigorous stirring. Afterwards, tert-butanol (10 ml) was added to the previous solution immediately to initiate the demulsification. A precipitate was separated using centrifugation and washed with hexane. Finally, the precipitates were dried overnight in vacuum and collected. For CsPbCl3 and CsPbI3, same procedure was followed except the halide precursors where PbCl2 and PbI2 was dissolved in DMF initially, respectively. 2
2.2. Characterization: Please see supporting information (S.I.) †. 3. Results and discussion XRD patterns of the synthesized samples are presented in Fig. 1(a). Indexed peaks refer to orthorhombic structure of CsPbBr3 (JCPDS: 01-072-7929) and CsPbI3 (JCPDS:18-0376) and tetragonal phase of CsPbCl3 (JCPDS: 18-0366). All the diffraction peaks and corresponding planes are enlisted in Table-S1 (please see S.I.) †. High intensity of the diffraction peaks of CsPbX3 samples signify phase purity and high crystallinity.
Fig.1. (a) XRD (b) FTIR (c) reflectance (d, e, f) EDX Spectra with atomic percentage of the samples Fig. 1(b) shows Fourier transform infrared (FTIR) spectra of the samples. Two bands ~3030 and ~1640 cm-1 can be assigned to N-H symmetric stretching and N-H asymmetric bending mode respectively. Bands at 1505 and 1545 cm−1 are assigned to O-C-O asymmetric stretching mode. Strong dips at around ~2854 and ~2925 cm-1 are related with asymmetrical and symmetric stretching vibration of CH2 and CH3. Band at ~ 2925cm-1 signifies the presence oleic acid molecules on the surface of cubes. [10] C=O stretching mode
3
positioned at 1690 cm-1 in the spectrum also result from oleic acid. All the vibrational bands in this figure along with their corresponding modes are enlisted in detail in Table-S2 (please see S.I.) †.
Fig.2. FESEM images of a-c) CsPb(Cl3,Br3,I3). Insets show single cube (d) HRTEM image of CsPbCl3 Fig. 1(c) shows the reflectance spectra of the samples. Sharp diminution in reflectance percentage indicates high crystalline nature of the cubes. Assessed values of optical band gap from the corresponding spectrum are found to be ~2.34, ~2.78 and ~2.98 eV for CsPbBr3, CsPbI3 and CsPbCl3 respectively, which agrees well with the literature [11]. Difference in band gaps in these samples is associated with the compositions and ionic radius of the halide ions. Detail of such band gap variation is illustrated in supporting information (please see S.I.). EDX spectra with associated elemental percentage shown in Fig. 1(d-f) confirm the sole presence of Cs, Pb and corresponding halides (Cl, Br and I) in samples. Observed atomic ratio of the
4
constituting elements matches well with actual stoichiometry. Homogenous distribution of the constituent elements is obvious from the elemental mapping of the samples, presented in Fig S1 (please see S.I.) †. Fig. 2(a-c) shows the FESEM images of the synthesized samples. Morphological uniformity of the products is obvious form the low magnification image. Fig. 2a displays the FESEM image of the CsPbCl3 cube with side of 200 nm. CsPbBr3 cubes (Fig. 2b) possess relatively higher size compare to the CsPbCl3 sample. Each side of these cubes are~300 nm. Fig. 2c shows the FESEM images of CsPbI3 where average sizes of the cubes are higher than the previous two. Average size of CsPbI3 cubes are of 800 nm in each side. Fig. 2(d) shows the HRTEM image of CsPbCl3 cube. Parallel lines with spacing ~0.39 nm corresponding to [110] plane of orthorhombic phase of CsPbCl3 confirm the single crystallinity and corroborates with the XRD results. Photocatalytic activity of the samples was measured taking Eosin-B dye as the probe molecules under visible light. To obtain the adsorption/desorption equilibrium between dye and samples, all the samples were stirred for 100 minutes in complete darkness. Evolution of the UV-vis absorption spectra of Eosin-B at different irradiation timeintervals as the result of the catalytic activity under light for all three samples are presented in Fig. 3(a-c). Intensity of the characteristic’s absorption peak ~520 nm is gradually decreased with the increase of irradiation time. After 140 minutes, characteristic absorptions were found to decrease by 90% for CsPbCl3. After 210 minutes, absorptions of CsPbBr3 and CsPbI3 were found to be decreased by 82% and 73% respectively with respect to their initial dye concentration. It clearly proves that CsPbCl3 is more active than the other two perovskites. Photo-degradation ability of the cubes were further analysed quantitatively considering the decrease in dye content (C/C0) as a function of time (Fig. 3d) where C0 and C signify the initial dye concentration after dark stirring (t=0) and final concentration (at time t) respectively. Superior degradation ability of CsPbCl3 as compared to other two is obvious from this graph. Degradation of Eosin-B follows the pseudo first order expression: ln(C0/C) = kappC where kapp is apparent pseudo first order rate constant. Values of kapp for all samples are estimated from the slopes of ln(C0/C) versus time graph (Fig. 3e) and enlisted in the inset. kapp value is found to be for maximum CsPbCl3 which is 2-fold greater than the same for CsPbI3. Such high catalytic efficiency as compared to other two was also observed by Gao et al. [8]. 5
Fig. 3. Temporal evolution of UV-vis spectra of Eosin-B for a) CsPbCl3 b) CsPbBr3 and c) CsPbI3; d) decrease in dye concentration with times e) kinetic plots f) degradation percentage of the samples. Photocatalysis under visible light by the CsPbX3 cubes can be explained as follows: irradiation on the aqueous suspension of CsPbX3 by light with photon energy higher or equal to the band gap leads excitation of valance band electron to conduction band leaving a hole in valance band. Redox potential of H2O (OH‾/OH•) and (O2/•O2-) lies within the bandgap of CsPbX3. [8] Thus, oxygen may act as an electron acceptor can form 6
•O -. 2
These superoxide radicals turn indirectly into highly reactive hydroxide radicals (OH•). Simultaneously,
photogenerated holes also can react with the water adhere on the surface of the CsPbX3 cubes to form OH•. These highly reactive OH• radicals generated though either photogenerated electrons or holes oxidizes the dyes [8, 12]. Reaction mechanism involved in the dye degradation can be expressed as follows: CsPbX3 cubes + hν → e- + h+ O2+ e- →•O2H2O+ h+→ OH•+ H+ Dye + OH•→ Dye mineralization. Reusability of the catalyst, another important issue for their repetitive usage as catalyst was also examined for CsPbCl3 over 3 cycles under light using the same catalyst. Photocatalytic activity of the cubes does not change significantly after the cycles which confirm high stability during the catalytic reaction. High photo-stability of the CsPbCl3 cubes is associated with its high crystallinity, as is obvious from the HRTEM observations. FTIR spectrum of CsPbCl3 taken after photocatalysis is presented in Fig. S2 (please see S.I.) †. No such discernible differences with the previous spectrum signify the high durability of the catalyst.
4. Conclusion: We have prepared all-inorganic cesium lead halide cubes via a facile, environmentally friendly, solution phase synthesis procedure. As grown CsPbX3 cubes are highly crystalline in nature. Photocatalytic performance of synthesised cubes is explored for degradation of Eosin-B. CsPbCl3 cubes showed maximum catalytic performance under light whereas CsPbI3 delivered nominal performance among all. Additionally, CsPbCl3 cubes display good recyclability and photo-stability, important criteria for good photocatalysts. These results suggest the usage potential of CsPbCl3 cubes as high-performance visible light photocatalyst.
Acknowledgement: Dr. Sayantani Das wants to acknowledge SERB-NPDF (DST) (File No: PDF/2017/001938) for financial support throughout the project.
7
References: 1. W. S. Yang, J. H. Noh, N. J. Jeon, Y. C. Kim, S. Ryu, J. Seo, S. I. Seok, Science, 348 (2015) pp. 1234– 1237. 2. L. Su, Z. Zhao, H. Li, Y. Wang, S. Kuang, G. Cao, Z. Wang and G. Zhu, J. Mater. Chem. C 4 (2016) pp. 10395–10399. 3. D. Chen, S. Yuan, J. Chen, J. Zhong, X. Xu, J. Mater. Chem. C 6 (2018) pp.12864-12870. 4. C. C. Stoumpos, M.G. Kanatzidis, Acc. Chem. Res. 48 (2015) pp. 2791-2802. 5. M.G. Walter, E.L. Warren, J. R. McKone, S.W. Boettcher, Q. Mi, E.A. Santori, N.S. Lewis, Chem. Rev. 110 (2010) pp. 6446–6473. 6. Z. Li, W. Luo, M. Zhang, J. Feng, Z. Zou, Energy Environ.Sci. 6 (2013) pp. 347–370. 7. S. Maiti, S. Pal, K.K. Chattopadhyay, CrystEngComm 17 (2015) pp. 9264-9295. 8. G. Gao, Q. Xi, H. Zhou, Y. Zhao, C. Wu, L. Wang, P. Guo, J. Xu, Nanoscale 9 (2017) pp. 12032–12038. 9. T. Paul, D. Das, B. K. Das, S. Sarkar, S. Maiti, K.K. Chattopadhyay, J. Hazard. Mater. 380 (2019) pp. 120855. 10. C. Yajing, J.Y. Young, L. Guopeng, X. Enze, Y. Shengtao, L. C.-Hsin, W. Zewei, H. Yanjie, H.L. Chun, K.W. Brent, V.T. Vladimir, K. Zhitao, T. Naresh J. Yang, L. Zhiqun, ACS Appl. Mater. Interfaces 10 (2018) pp. 37267-37276. 11. X. Li, Y. Wu, S. Zhang, B. Cai, Y. Gu, J. Song and H. Zeng, Adv. Funct. Mater. 26 (2016) pp. 2435-2445. 12. U. N. Maiti, S. Maiti and K. K. Chattopadhyay, CrystEngComm, 14 (2012) pp. 640–647
8
S0167-577X(20)30206-8 https://doi.org/10.1016/j.matlet.2020.127501 MLBLUE 127501
To appear in:
Materials Letters
Received Date: Revised Date: Accepted Date:
16 December 2019 12 February 2020 13 February 2020
Please cite this article as: S. Das, T. Paul, S. Maiti, K. Kumar Chattopadhyay, Ambient Processed CsPbX3 Perovskite Cubes for Photocatalysis, Materials Letters (2020), doi: https://doi.org/10.1016/j.matlet.2020.127501
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
© 2020 Published by Elsevier B.V.
Ambient Processed CsPbX3 Perovskite Cubes for Photocatalysis Sayantani Das1, Tufan Paul2, Soumen Maiti3, Kalyan Kumar Chattopadhyay1,2, * 1Department 2School
of Physics, Jadavpur University, Kolkata 700032, Jadavpur.
of Materials Science and Nanotechnology, Jadavpur University, Kolkata 700032, Jadavpur. 3St.
Thomas College of Engineering & Technology, Kolkata 700023, India *Corresponding author email: [email protected]
Abstract All-inorganic cesium lead halide (CsPbX3, X= Cl, Br or I) perovskite cubes have been prepared by low-cost solution-based technique at room temperature. As synthesized perovskites were characterised by XRD, FESEM, TEM and FTIR. Photocatalytic activity of the as-synthesized cubes was investigated taking hazardous Eosin-B dye as model contaminants. Among all the synthesised samples CsPbCl3 cubes showed superior catalytic performance and degraded the dye solution within 140 minutes under visible light. Going beyond well reported catalytic study on CsPbX3 quantum dots, this study not only establishes the potential of CsPbX3 cubes in dye degradation also provides new insight on the impact of morphology on it.
Keywords: X-ray techniques, FTIR, Electron microscopy 1. Introduction: Recently, organic-inorganic hybrid perovskites have truncated a considerable attention both from academia and industrial field due to their low-cost solution processing, tunable bandgap, long diffusion length, high charge carrier mobility and large absorption coefficients [1, 2]. All inorganic perovskites with chemical formula ABX3 are generally stable in orthorhombic crystal structure at room temperature, where A and B stand for two cations with dissimilar sizes (generally A = Rb+ or Cs+ and B = Sn+ or Pb+) and X denotes for anion
1
(halides: X = F-, Cl-, Br-and I-). All inorganic CsPbX3 possess several unique features like ultra-high photoluminescence quantum yield, excellent stability, narrow band emission etc. [3, 4]. Textile effluents from industrial waste has polluted the water and make it unfit for consumption [5,6]. Such sewage contaminated water is carcinogenic and poses serious threat to human health. Degradation and conversion of these hazardous contaminants into harmless one is essential. Numerous strategies have been adopted for wastewater purification, among which heterogeneous catalysis under light is widely accepted due to its high efficiency, non-selectivity and cost effectiveness [7]. Photocatalysis employing transition metal oxides is well presented in literature [7]. However, exploration of aforesaid using all inorganic halide perovskites is still lacking. Though there are few reports on photocatalysis by all inorganic halide perovskites however most of them based on quantum dots [8, 9]. Here, adopting a facile, budgetary approach we have realized CsPbX3 cubes. Only changes in halide reagent in similar synthesis protocol lead to different cesium lead halide cubes. We have examined the catalytic behaviour of CsPbX3 cubes using Eosin-B under visible light. Registered results suggest variance in catalytic performance and highest efficiency of CsPbCl3 cube as compare to others. Being not restricted to quantum dot, photocatalytic analysis of these CsPbX3 cubes will provide a new insight on the impact of catalyst geometry on photocatalysis.
2.1 Experimental For the synthesis of CsPbBr3, initially PbBr2 (0.36 mg) was dissolved in 2 ml DMF. An oil phase was prepared by adding hexane (10 ml) to oleic acid (1.0 ml) and n-octylamine (0.25 ml). After that CsBr (0.21 mg) was added slowly into the PbBr2 solution and the final solution was mixed into the oil phase under vigorous stirring. Afterwards, tert-butanol (10 ml) was added to the previous solution immediately to initiate the demulsification. A precipitate was separated using centrifugation and washed with hexane. Finally, the precipitates were dried overnight in vacuum and collected. For CsPbCl3 and CsPbI3, same procedure was followed except the halide precursors where PbCl2 and PbI2 was dissolved in DMF initially, respectively. 2
2.2. Characterization: Please see supporting information (S.I.) †. 3. Results and discussion XRD patterns of the synthesized samples are presented in Fig. 1(a). Indexed peaks refer to orthorhombic structure of CsPbBr3 (JCPDS: 01-072-7929) and CsPbI3 (JCPDS:18-0376) and tetragonal phase of CsPbCl3 (JCPDS: 18-0366). All the diffraction peaks and corresponding planes are enlisted in Table-S1 (please see S.I.) †. High intensity of the diffraction peaks of CsPbX3 samples signify phase purity and high crystallinity.
Fig.1. (a) XRD (b) FTIR (c) reflectance (d, e, f) EDX Spectra with atomic percentage of the samples Fig. 1(b) shows Fourier transform infrared (FTIR) spectra of the samples. Two bands ~3030 and ~1640 cm-1 can be assigned to N-H symmetric stretching and N-H asymmetric bending mode respectively. Bands at 1505 and 1545 cm−1 are assigned to O-C-O asymmetric stretching mode. Strong dips at around ~2854 and ~2925 cm-1 are related with asymmetrical and symmetric stretching vibration of CH2 and CH3. Band at ~ 2925cm-1 signifies the presence oleic acid molecules on the surface of cubes. [10] C=O stretching mode
3
positioned at 1690 cm-1 in the spectrum also result from oleic acid. All the vibrational bands in this figure along with their corresponding modes are enlisted in detail in Table-S2 (please see S.I.) †.
Fig.2. FESEM images of a-c) CsPb(Cl3,Br3,I3). Insets show single cube (d) HRTEM image of CsPbCl3 Fig. 1(c) shows the reflectance spectra of the samples. Sharp diminution in reflectance percentage indicates high crystalline nature of the cubes. Assessed values of optical band gap from the corresponding spectrum are found to be ~2.34, ~2.78 and ~2.98 eV for CsPbBr3, CsPbI3 and CsPbCl3 respectively, which agrees well with the literature [11]. Difference in band gaps in these samples is associated with the compositions and ionic radius of the halide ions. Detail of such band gap variation is illustrated in supporting information (please see S.I.). EDX spectra with associated elemental percentage shown in Fig. 1(d-f) confirm the sole presence of Cs, Pb and corresponding halides (Cl, Br and I) in samples. Observed atomic ratio of the
4
constituting elements matches well with actual stoichiometry. Homogenous distribution of the constituent elements is obvious from the elemental mapping of the samples, presented in Fig S1 (please see S.I.) †. Fig. 2(a-c) shows the FESEM images of the synthesized samples. Morphological uniformity of the products is obvious form the low magnification image. Fig. 2a displays the FESEM image of the CsPbCl3 cube with side of 200 nm. CsPbBr3 cubes (Fig. 2b) possess relatively higher size compare to the CsPbCl3 sample. Each side of these cubes are~300 nm. Fig. 2c shows the FESEM images of CsPbI3 where average sizes of the cubes are higher than the previous two. Average size of CsPbI3 cubes are of 800 nm in each side. Fig. 2(d) shows the HRTEM image of CsPbCl3 cube. Parallel lines with spacing ~0.39 nm corresponding to [110] plane of orthorhombic phase of CsPbCl3 confirm the single crystallinity and corroborates with the XRD results. Photocatalytic activity of the samples was measured taking Eosin-B dye as the probe molecules under visible light. To obtain the adsorption/desorption equilibrium between dye and samples, all the samples were stirred for 100 minutes in complete darkness. Evolution of the UV-vis absorption spectra of Eosin-B at different irradiation timeintervals as the result of the catalytic activity under light for all three samples are presented in Fig. 3(a-c). Intensity of the characteristic’s absorption peak ~520 nm is gradually decreased with the increase of irradiation time. After 140 minutes, characteristic absorptions were found to decrease by 90% for CsPbCl3. After 210 minutes, absorptions of CsPbBr3 and CsPbI3 were found to be decreased by 82% and 73% respectively with respect to their initial dye concentration. It clearly proves that CsPbCl3 is more active than the other two perovskites. Photo-degradation ability of the cubes were further analysed quantitatively considering the decrease in dye content (C/C0) as a function of time (Fig. 3d) where C0 and C signify the initial dye concentration after dark stirring (t=0) and final concentration (at time t) respectively. Superior degradation ability of CsPbCl3 as compared to other two is obvious from this graph. Degradation of Eosin-B follows the pseudo first order expression: ln(C0/C) = kappC where kapp is apparent pseudo first order rate constant. Values of kapp for all samples are estimated from the slopes of ln(C0/C) versus time graph (Fig. 3e) and enlisted in the inset. kapp value is found to be for maximum CsPbCl3 which is 2-fold greater than the same for CsPbI3. Such high catalytic efficiency as compared to other two was also observed by Gao et al. [8]. 5
Fig. 3. Temporal evolution of UV-vis spectra of Eosin-B for a) CsPbCl3 b) CsPbBr3 and c) CsPbI3; d) decrease in dye concentration with times e) kinetic plots f) degradation percentage of the samples. Photocatalysis under visible light by the CsPbX3 cubes can be explained as follows: irradiation on the aqueous suspension of CsPbX3 by light with photon energy higher or equal to the band gap leads excitation of valance band electron to conduction band leaving a hole in valance band. Redox potential of H2O (OH‾/OH•) and (O2/•O2-) lies within the bandgap of CsPbX3. [8] Thus, oxygen may act as an electron acceptor can form 6
•O -. 2
These superoxide radicals turn indirectly into highly reactive hydroxide radicals (OH•). Simultaneously,
photogenerated holes also can react with the water adhere on the surface of the CsPbX3 cubes to form OH•. These highly reactive OH• radicals generated though either photogenerated electrons or holes oxidizes the dyes [8, 12]. Reaction mechanism involved in the dye degradation can be expressed as follows: CsPbX3 cubes + hν → e- + h+ O2+ e- →•O2H2O+ h+→ OH•+ H+ Dye + OH•→ Dye mineralization. Reusability of the catalyst, another important issue for their repetitive usage as catalyst was also examined for CsPbCl3 over 3 cycles under light using the same catalyst. Photocatalytic activity of the cubes does not change significantly after the cycles which confirm high stability during the catalytic reaction. High photo-stability of the CsPbCl3 cubes is associated with its high crystallinity, as is obvious from the HRTEM observations. FTIR spectrum of CsPbCl3 taken after photocatalysis is presented in Fig. S2 (please see S.I.) †. No such discernible differences with the previous spectrum signify the high durability of the catalyst.
4. Conclusion: We have prepared all-inorganic cesium lead halide cubes via a facile, environmentally friendly, solution phase synthesis procedure. As grown CsPbX3 cubes are highly crystalline in nature. Photocatalytic performance of synthesised cubes is explored for degradation of Eosin-B. CsPbCl3 cubes showed maximum catalytic performance under light whereas CsPbI3 delivered nominal performance among all. Additionally, CsPbCl3 cubes display good recyclability and photo-stability, important criteria for good photocatalysts. These results suggest the usage potential of CsPbCl3 cubes as high-performance visible light photocatalyst.
Acknowledgement: Dr. Sayantani Das wants to acknowledge SERB-NPDF (DST) (File No: PDF/2017/001938) for financial support throughout the project.
7
References: 1. W. S. Yang, J. H. Noh, N. J. Jeon, Y. C. Kim, S. Ryu, J. Seo, S. I. Seok, Science, 348 (2015) pp. 1234– 1237. 2. L. Su, Z. Zhao, H. Li, Y. Wang, S. Kuang, G. Cao, Z. Wang and G. Zhu, J. Mater. Chem. C 4 (2016) pp. 10395–10399. 3. D. Chen, S. Yuan, J. Chen, J. Zhong, X. Xu, J. Mater. Chem. C 6 (2018) pp.12864-12870. 4. C. C. Stoumpos, M.G. Kanatzidis, Acc. Chem. Res. 48 (2015) pp. 2791-2802. 5. M.G. Walter, E.L. Warren, J. R. McKone, S.W. Boettcher, Q. Mi, E.A. Santori, N.S. Lewis, Chem. Rev. 110 (2010) pp. 6446–6473. 6. Z. Li, W. Luo, M. Zhang, J. Feng, Z. Zou, Energy Environ.Sci. 6 (2013) pp. 347–370. 7. S. Maiti, S. Pal, K.K. Chattopadhyay, CrystEngComm 17 (2015) pp. 9264-9295. 8. G. Gao, Q. Xi, H. Zhou, Y. Zhao, C. Wu, L. Wang, P. Guo, J. Xu, Nanoscale 9 (2017) pp. 12032–12038. 9. T. Paul, D. Das, B. K. Das, S. Sarkar, S. Maiti, K.K. Chattopadhyay, J. Hazard. Mater. 380 (2019) pp. 120855. 10. C. Yajing, J.Y. Young, L. Guopeng, X. Enze, Y. Shengtao, L. C.-Hsin, W. Zewei, H. Yanjie, H.L. Chun, K.W. Brent, V.T. Vladimir, K. Zhitao, T. Naresh J. Yang, L. Zhiqun, ACS Appl. Mater. Interfaces 10 (2018) pp. 37267-37276. 11. X. Li, Y. Wu, S. Zhang, B. Cai, Y. Gu, J. Song and H. Zeng, Adv. Funct. Mater. 26 (2016) pp. 2435-2445. 12. U. N. Maiti, S. Maiti and K. K. Chattopadhyay, CrystEngComm, 14 (2012) pp. 640–647
8