Self‐templated fabrication of 2-D dual nanoarchitecture Zn_1-xCd_xS porous nanosheet and ZnO nanorod for photoelectrochemical hydrogen production

Herein, dual nanostructured ZnO nanorod (NR)-Zn_1-xCd_xS porous nanosheet (PNS) photoanodes were produced on a zinc foil through cation exchange reaction of inorganic–organic hybrid ZnS(en)_0.5 nanosheets. ZnS(en)_0.5 NS's photoanodes have been synthesized via a facile solvothermal method followed by a series of cadmium (Cd²⁺) ion-exchange using various ion-exchange reaction times and temperatures. During Cd²⁺ ion-exchange, the Zn_1-xCd_xS PNS and a new type of vertically aligned ZnO NR were subsequently grown on the zinc foil substrate. The different exposed surfaces of the vertically aligned hexagonal ZnO NR and Zn_1-xCd_xS PNS photoanodes contribute to appropriate morphology, effective light harvesting, and efficient charge separation in ZnO-NR-Zn_1-xCd_xS PNS160C. The optimum ZnO NR-Zn_1-xCd_xS PNS160C photoanode contributed the highest photocurrent density of 6.60 mA·cm⁻² and hydrogen production of 250.65 μmol·cm⁻² at 0 V vs. Ag/AgCl. Finally, the charge transfer mechanism in the optimum photoanode is discussed in detail.