InGaN nanorods/CuBi2O4 heterojunction photoanodes for photoelectrochemical water splitting

Semiconductor heterojunctions designed by a rational energy band structure can be well accelerated for charge separation, which leads to improved photoelectrochemical (PEC) performance. Using an economical HCVD process, one-dimensional InGaN nanorods were produced in this work. CuBi2O4 was successfully loaded onto the surface of InGaN nanorods using electrodeposition and annealing techniques to produce p-n heterojunction n-InGaN/p-CuBi2O4 photoanodes for the first time. Attributed to the suitable energy band structure, the resulting heterojunction photoanodes exhibit effective charge separation and transfer through the potential gradient. The optimized photoanode achieves a photocurrent density of 5.6 mA/cm2 at 1.23 V vs. RHE, which is 10.2 times greater than that of pure InGaN nanorods. In addition, the InGaN/CuBi2O4 heterojunction exhibits improved stability over previous work. This work paves the path for the rational design and construction of heterojunction photoanodes based on InGaN.