Efficient Indium Sulfide Photoelectrode with Crystal Phase and Morphology Control for High-Performance Photoelectrochemical Water Splitting

Crystal phase control of materials plays an important role on their properties in photocatalysis and photoelectrocatalysis. Herein, cubic and tetragonal phase control of In2S3 photoanodes with various morphologies on indium tin oxide transparent conductive glass substrate have been successfully realized through a simple hydrothermal method for the first time. According to the detailed characterization analysis, we proposed a model to interpret the phase transition of In2S3 along with hydrothermal reaction time. The photoelectrochemical tests suggest that the cubic phase In2S3 nanocubes with cuneiform morphology exhibit a photocurrent density of 0.50 mA/cm(2) at 1.23 V vs RHE benefit by the special structure for efficient charge separation and transfer. This is the highest photocurrent values of single In2S3 crystals best to our knowledge. Furthermore, the photoelectrochemical performance of In2S3 can be greatly improved by depositing a Co-Pi cocatalysts layer. The composites show a 1.36-fold increase of photocurrent density (0.68 mA/cm(2) at 1.23 V vs RHE) compared to that of pristine In2S3. This work highlights that In2S3 can be an attractive candidate as photoanodes for photoelectrochemical water splitting, and the crystal phase control presents a new avenues to the exploration and design of photoelectrodes for realizing superior performances.