Fabrication of CdSe nanosheet/CdS nanorod heterojunctions through topotactic transformation of self-template photoanode for enhanced photoelectrochemical hydrogen production

In this study, a CdSe nanosheet (NS)/CdS nanorod (NR) photoanode was developed using solvothermal, microwave-assisted, and self-template conversion techniques. The process commenced with the synthesis of CdSNRs through a solvothermal method. Subsequently, an inorganic-organic CdSe(en)_0.5NS/CdSNR electrode was fabricated via a microwave-assisted approach. During the following hydrothermal step, the organic components were eliminated, resulting in a porous CdSeNS/CdSNR photoanode. The optimized photoelectrode exhibited a photocurrent density of 8.1 mA cm⁻² (0 V vs. Ag/AgCl) and produced 554 μmol cm⁻² of hydrogen over 3 hours under one-sun illumination. The enhanced photoelectrochemical (PEC) performance can be attributed to topotactic transformation, augmented light absorption, enhanced charge separation, and increased surface area. This innovative porous heterojunction design not only offers an effective strategy for promoting charge-transfer pathways but also establishes a scalable platform for green hydrogen production.