Synergistic effect of interstitial phosphorus doping and MoS2 modification over Zn0.3Cd0.7S for efficient photocatalytic H2 production.

ABSTRACT

ZnxCd1-xS photocatalysts have been widely investigated due to their diverse morphologies, suitable band gaps/band edge positions, and high electronic mobility. However, the sluggish charge separation and severe charge recombination impede the application of ZnxCd1-xS for hydrogen evolution reaction (HER). Herein, doping of phosphorus (P) atoms into Zn0.3Cd0.7S has been implemented to elevate S vacancies concentration as well as tune its Fermi level to be located near the impurity level of S vacancies, prolonging the lifetime of photogenerated electrons. Moreover, P doping induces a hybridized state in the bandgap, leading to an imbalanced charge distribution and a localized built-in electric field for effective separation of photogenerated charge carriers. Further construction of intimate heterojunctions between P-Zn0.3Cd0.7S and MoS2 accelerates surface redox reaction. Benefiting from the above merits, 1 % MoS2/P-Zn0.3Cd0.7S exhibits a high hydrogen production rate of 30.65 mmol·g-1·h-1 with AQE of 22.22 % under monochromatic light at 370 nm, exceeding most ZnxCd1-xS based photocatalysts reported so far. This work opens avenues to fabricate examplary photocatalysts for solar energy conversion and beyond.