Ligand-free Cs2PdBr6 perovskite microcrystals with narrow bandgap and high photoelectrochemical performance in aqueous solution

The exploration of efficient lead-free perovskite photoelectric active materials to develop high-performance photoelectrochemical (PEC) systems in aqueous solution is crucial to expand their PEC applications. Herein, we successfully constructed a high-performance PEC platform using ligand-free perovskite Cs2PdBr6 2 PdBr 6 microcrystals (MCs) as the photoactive substance. The Cs2PdBr6 2 PdBr 6 MCs showed narrow bandgap, wide absorption range, high electronic mobility and good stability in aqueous solutions. Particularly, the Cs2PdBr6 2 PdBr 6 MCs exhibited an excellent photoresponse, the photocurrent density could reach as high as 98 mu A/cm2 2 under 10.18 mW/cm2 2 light irradiation in the absence of other electron acceptors. In addition of the extremely wide range of response wavelength, wide pH range and accelerated interfacial carrier transfer, the Cs2PdBr6 2 PdBr 6 MCs demonstrated the significant potential of photocathode active material for applications in PEC sensors and optoelectronic devices. Therefore, this work indicates that Cs2PdBr6 2 PdBr 6 MCs design is a highly efficient way to solve the intrinsic issues of perovskite material, predicting a promising strategy for high performance PEC application in aqueous ambience.