Amorphous molybdenum sulfide catalysts (MoS x ) can efficiently catalyze the H 2 evolution reaction (HER); however, their catalytic activities are still limited that need to be improved. Herein, transition metal-promoted MoS x H 2 evolution catalysts were facilely fabricated through an in-situ photochemical reduction with inexpensive organic dye as photosensitizers. Under visible light (λ ≥ 420 nm), the promotional effect of transition metals on the H 2 evolution over MoS x follows the order of Co > Fe ≈ Ni > unpromoted > Cu > Zn in Erythrosin B-triethanolamine (ErB-TEOA) system. The most active Co-promoted MoS x (Co-MoS x ) catalyst is amorphous and composed of inter-connected nanoparticles with diameters of 30–50 nm. The Co-MoS x catalyst contains both CoMoS phase and Co oxides/hydroxides. At the optimal reaction conditions, the Co-MoS x catalyst with Co:Mo ratio of 4:6 exhibits enhanced H 2 evolution activity by 2 times as compared to unpromoted MoS x and turnover numbers (TONs) of 30 and 60 based on ErB and catalyst used, respectively. The Co-MoS x catalyst also shows a long-term stability without noticeable activity degradation. The formation pathways of Co-MoS x catalyst and the photocatalytic mechanism for enhanced H 2 evolution performance were studied and a two-step reaction mechanism involved an oxidative quenching pathway of dye was proposed. This study demonstrates that in-situ concurrent photochemical fabrication with transition metal modification of amorphous MoS x catalyst is an effective strategy for development of MoS x -based HER catalysts with enhanced performances.
Hou, J., Lei, Y., Wang, F., Ma, X., Min, S., Jin, Z., & Xu, J. (2017). In-situ photochemical fabrication of transition metal-promoted amorphous molybdenum sulfide catalysts for enhanced photosensitized hydrogen evolution. International Journal of Hydrogen Energy, 42(16), 11118–11129. https://doi.org/10.1016/j.ijhydene.2017.01.235