Heterojunction CdS/CuO/ZnO branched nanowire photoelectrodes for efficient photoelectrochemical water splitting

Developing of novel photoelectrode materials with high durability and efficiency is a key step for practical realization of solar driven photoelectrochemical (PEC) water splitting. Herein, we report a rational and simple approach to fabricate heterojunction CdS/CuO/ZnO branched nanowires serving as the photoelectrodes with boosted PEC efficiency toward highly efficient water splitting. The ZnO branched nanowires were first hydrothermally synthesized from electrospun ZnO nanofibers followed by decorating of CuO nanoparticles via photoreduction. Finally, CdS nanoparticles were wrapped thoroughly the CuO/ZnO heterojuction by chemical bath deposition that form a socalled ternary core-shell structure. The optimized heterojunction CdS/CuO/ZnO branched nanowire photoelectrode displays a significantly enhanced photoconversion efficiency of 3.9% under solar simulation, which is 1.8, 18 and 30 times higher than that of the corresponding CdS/ZnO, CuO/ZnO and pristine ZnO branched nanowire photoelectrodes, respectively. The largest hydrogen production was measured to be 1.7 mL cm(-2) upon 3600 s exposure time, which is about 1.7 times greater than that of the CdS/ZnO electrode and in line with the one extrapolated from the PEC water splitting measurement. Our finding provides a rational strategy for the design of highly efficient and durable photoelectrodes for PEC water splitting process.

Automated summary

We reported a rational and simple approach to fabricate heterojunction CdS/CuO/ZnO branched nanowires as photoelectrodes for highly efficient water splitting. The optimized photoelectrode showed significantly enhanced photoconversion efficiency of 3.9% under solar simulation, which is much higher than other photoelectrodes.