Hexagonal phase/cubic phase homogeneous ZnIn2S4 n-n junction photoanode for efficient photoelectrochemical water splitting

One of the most efficient ways to achieve a high performance of photoelectrochemical (PEC) water splitting is to accelerate the separation and transfer of photogenerated carriers. Homojunction has the perfect advantages due to the appropriate band gap and the close combination of interphase similar lattices between the two semiconductors. Herein, we report a rational and low-cost design that hexagonal phase/cubic phase homogeneous ZnIn2S4 n-n junction on FTO conductive substrate is fabricated through a simple two-step hydrothermal method to realize enganced PEC performance. In addition, the chemical reaction process and mechanism are discussed in detail. The hexagonal phase/cubic phase homogeneous ZnIn2S4 n-n junction have an excellent photocurrent density of 0.53 mA/cm2 at 1.23 V vs RHE, which is 1.36 and 1.89 times increased than that of the hexagonal phase ZnIn2S4 and cubic phase ZnIn2S4, respectively. Moreover, this work will be instructive for the design of efficient photoelectrode system which used in the photoelectrochemical water splitting.