Uniform H-CdS@NiCoP core-shell nanosphere for highly efficient visible-light-driven photocatalytic H2 evolution.

Constructing highly efficient and cost-effective photocatalyst system has been a big challenge for photocatalysis. Herein, CdS nanosphere (N-CdS), hollow CdS (H-CdS) and a series of H-CdS@NiCoP core-shell nanospheres have been successfully prepared via a facile hydrothermal method. The activity test showed that H-CdS exhibited higher photocatalytic activity (3.34 mmol g-1h-1) compared with N-CdS (0.99 mmol g-1h-1) under visible light irradiation (λ ≥ 420 nm), suggesting that hollow structure could effectively improve photocatalytic activity. Moreover, the H-CdS@NiCoP-7 wt% displayed a maximum photocatalytic H2 evolution rate of 13.47 mmol g-1h-1, which was about 4 times and 2.5 times higher than that of pristine H-CdS and H-CdS@Pt-3 wt%, respectively. Furthermore, H-CdS@NiCoP-7 wt% exhibited a good stability during 20 h test. The physicochemical properties were characterized by XRD, SEM, TEM, XPS, UV-vis DRS, PL and photoelectrochemical technique. The results showed that NiCoP addition can construct p-n junction with H-CdS and effectively promote the charge transfer from CdS to NiCoP, which improved the photocatalytic hydrogen evolution activity. This work revealed that NiCoP could react as an excellent co-catalyst for enhancing H-CdS photocatalytic activity.