Self-assembly optimization of cadmium/molybdenum sulfide hybrids by cation coordination competition toward extraordinarily efficient photocatalytic hydrogen evolution

Abstract

Combining photoharvesting semiconductors with MoS₂ co-catalysts is an intriguing approach to develop inexpensive and efficient photocatalysts for visible-light-driven hydrogen (H₂) evolution; however, how to coordinate light absorbers and catalytic sites still remains a great challenge. Here, we propose a facile strategy for optimizing assembly of CdS–MoS₂ (CM) nanohybrids with controlled active edge exposure by cation coordination competition in one-pot solvothermal synthesis. With the involvement of Cd ions, more formed CdS nanocrystals coordinated preferentially with MoS₂ edges self-optimize into unique CM hybrids, which enables the maximum performances of active area and photo-induced electron transfer and injection into the photocatalytic H₂ evolution reaction (HER). As a result, the optimum CM hybrids exhibit an outstanding and stable photocatalytic activity with a H₂ evolution rate of up to 1009 mmol h⁻¹ g⁻¹, more than 10⁴-fold higher than that of pure CdS, which is the best among the state-of-the-art heterogeneous photocatalysts. This work provides a facile strategy for a controlled configuration of MoS₂ edge active sites on photoharvesting semiconductors toward high-efficiency solar photocatalytic H₂ generation.