Exploring halide perovskite nanocrystal decomposition:Insight by insitu electron paramagnetic resonance spectroscopy  

作　　者：Anastasiya Sedova Philip N.Immanuel Raanan Carmieli Hila Shalom Achiad Goldreich Alen S.Thomas Jonathan Prilusky Akshay Puravankara Ido Bar-On Lena Yadgarov 

机构地区：[1]Department of Chemical Engineering,Ariel University,Ariel 4076414,Israel [2]Department of Molecular Chemistry and Materials Science,Weizmann Institute of Science,Rehovot 7610001,Israel [3]Department of Chemical Research Support,Weizmann Institute of Science,Rehovot 7610001,Israel

出　　处：《Nano Research》2025年第3期322-332,共11页纳米研究(英文版)

基　　金：financial support from the Ministry of Energy,Israel,through their support of this research under contract numbers 221-11-042,223-11-043,and 223-11-046.

摘　　要：Zero-dimensional(0D)and three-dimensional(3D)halide perovskite nanocrystals(HP-NCs),owing to their unique optoelectronic properties,are extensively studied for photocatalytic activity.However,HPs are highly sensitive to light,humidity,and other environmental factors,which accelerate their decomposition.Understanding the decomposition process is crucial for gaining insights into how to stabilize HP-NCs.Here,we investigate the radical-driven decomposition process and dynamics of the 0D Cs_(4)PbBr_(6)and 3D CsPbBr_(3)NCs under the influence of visible light and a polar solvent by electron paramagnetic resonance(EPR)spectroscopy.Our findings indicate that light accelerates radical formation over time,making the decomposition of HP-NCs a self-sustaining process.Upon illumination of the NCs,hydroperoxyl radicals are formed first,followed by unconventional Br,Cs,and Pb-related radicals,indicating the initiation of NC decomposition.The decomposition of CsPbBr_(3)NCs starts after 3 min of light exposure,while Cs_(4)PbBr_(6)NCs take 18 min,indicating the greater stability of the latter.Additionally,we evaluated the photocatalytic activity of the HPs toward degrading organic dyes.The 3D CsPbBr_(3)NCs performed as superior photocatalysts compared to their 0D Cs_(4)PbBr_(6)NCs counterparts.Yet,linking the results of EPR measurements with the photocatalytic efficacy suggests that the CsPbBr_(3)NCs undergo degradation during the photocatalytic process,thereby serving as a sacrificial agent to enhance photocatalytic activity.The understanding derived from EPR spectroscopy in tracking radical formation and dynamics can be extended to enhance the stability and efficiency of various nanomaterials in optoelectronic and photocatalytic applications,thus contributing to advancements beyond the HP family.

关 键 词：halide perovskites electron paramagnetic resonance spectroscopy PHOTOCATALYSIS degradation stability 

分 类 号：TB383[一般工业技术—材料科学与工程]