Dual non-metal atom doping enabled 2D 1T-MoS2 cocatalyst with abundant edge-S active sites for efficient photocatalytic H-2 evolution

摘要

Metal-organic frameworks (MOFs) materials featured large specific surface area, unique porous structure and highly crystalline nature which rendered them ideal catalysts in solar light conversion. Generally, the catalytic H-2 generation activity of the MOFs was rather low which restricted its application. The effective co-catalyst introduction could enhance its overall performance via reducing the overpotential of hydrogen production while facili-tating charges transfer and increasing reactive sites. Herein, an two-dimensional (2D) O,P-MoS2 nanosheets cocatalyst with adequate edge-S active sites and high 1T-phase content were fabricated via co-doping of O and P atoms. Rational coupling the 2D O, P-MoS2 nanosheets with 2D NH2-MIL-125(Ti) nanoplate can afford greatly improved photocatalytic H-2 production rate of 339.3 mmol center dot g(-1)center dot h(-1), which was 11.6 and 6.7 times of pure NH2-MIL-125(Ti) and NH2-MIL-125(Ti)/commercial MoS2 composite, respectively. DFT calculation revealed that the edge-S serve as the active sites for H* adsorption rather than the plane-S and O sites in O, P-MoS2 or the O and S sites in O-MoS2. Compared with the commercial MoS2 with completely 2H-phase, the dual-doping can create higher-density unsaturated edge-S atoms and more 1T phase which can improve the reactivity of NH2-MIL-125(Ti) via inducing the breaking of Mo-S bonds and providing higher electrical conductivity. Dual non-metal atom doping of MoS2 cocatalyst featured abundant edge-S active centers and high concentration of 1T-phase offered a facile and effective method to developing highly efficient catalysts toward solar-energy conversion. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.