Photoelectrochemical Water Splitting Devices And Perovskite Solar Cells Based On Inverse Opal Structures

Currently,energy crisis has become a major issue that restricts world economic and social development.The depletion of traditional fossil energy such as coal,oil,and natural gas has made people urgently need to find a sustainable and clean energy source to reduce the use of fossil fuels.As an inexhaustible sustainable energy source,solar energy is considered as one of the most promising new energy sources in the future.However,it is difficult for humans to directly use the radiant energy of sunlight.Generally,solar energy is converted into electricity and chemical energy that can be used directly to store and utilize.Among them,perovskite solar cells and photoelectrochemical water splitting systems have been the research hotspots of solar energy applications in recent years and have received extensive attention from scientists all around the world.Up to now,various methods have been explored inorder to improve the solar energy conversion efficiency.Among them,reasonable electrode structure design has proved to be an effective method.For example,due to its unique optical properties and large specific surface area,the inverse opal?10?structure can effectively improve the light-capturing ability of the device and improve the photoelectric conversion efficiency.This article systematically studied the application of 10s in photoelectrochemical water splitting systems and inorganic perovskite solar cells,revealing the relationship between this structure and light capture,carrier transport,and photoelectric conversion efficiency.The main contents are listed as follows:?1?BiVO4/SnO2 inverse opal structure was prepared by the swell-to-shrink method and sol-gel method using monodisperse polystyrene microspheres as template,and the morphology of BiVO4/SnO2 was characterized by SEM and TEM.The UV-vis spectra were used to characterize the location of its photonic band gap.By virtue of adjusting the size of the polystyrene microsphere template,and the relationship between the microsphere size and the photonic band gap position of BiVO4/SnO2 was systematically studied.Using chloroauric acid as raw material,Au nanoparticles were prepared by sodium citrate reduction method.The surface plasma resonance peaks of the gold nanoparticles were characterized by UV-Vis spectra.Then,Au-BiVO4/SnO2 IO structure was prepared by adsorption method.By altering the size of the polystyrene?PS?spheres of the template and the size of Au NPs,the slow photon effect region could overlap with the SPR region of the Au NPs,resulting in a striking enhancement of incident light utilization.Applied as the photoanode of photoelectrochemical water splitting,the Au-BiVO4/SnO2 IO acquired enhanced photoelectrochemical performance,reaching 3.83 mA·cm-2 and an IPCE of 70.8%at 1.23 V vs RHE,which was more than 3 times higher than that of the planar BiVO4.The huge enhancement can be ascribed to the synergistic effect of the inverse opal nanostructure,the construction of heterostructure and the decoration of plasmonic nanoparticles.The work reported here provides promising strategies for design complex plasmon coupled semiconductor photoelectrodes to synergistically enhance PEC performance.?2?Inorganic perovskite inverse opal materials were prepared by sol-gel method using polystyrene microspheres as a template.The morphology of the perovskite inverse opals was measured by SEM to find the optimal reaction conditions for preparing inorganic perovskite-inverse opals.Optical properties were studied by UV-Vis spectra in order to find the relationship between the component of perovskites and the photonic band gaps.The photonic bandgap position was studied systematically by changing the size of the template,the angle of the incident light and the composition of the inorganic perovskite material.The carbon quantum dots?CQD?were prepared by the method of sugar pyrolysis,and CQD/CsPbBr3 IO was prepared by a one-step uploading method,which was applied as the light absorption layer of perovskite solar cells.Tunable optical response performance visible to naked eyes comes from the novel optical properties of photonic band gaps of CsPbBr3 IO are witnessed,which can be effectively regulated by means of adjusting the composition and the irradiation angles.Slow-photon effect originated from PBG efficiently strengthens the light utilization efficiency by slowing down the group velocity of photons near the location of PBG.Also,carbon quantum dot embedded among the IO frameworks displays enhanced light absorption ability and facilitates charge transfer process.Perovskite solar cells based on CQD/CsPbBr3 IO exhibit excellent stability and greatly improved PCE of 8.29%,more than 2 times higher than the planar CsPbBr3,which can be attributed to the optimized light harvesting ability,prolonged carrier lifetime and facilitated electron-hole extraction and injection process,which can be attributed to the synergetic effects of CQD and CsPbBr₃IO.