Dual non-metal atom doping enabled 2D 1T-MoS2 cocatalyst with abundant edge-S active sites for efficient photocatalytic H2 evolution

Abstract

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 H2 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 facilitating 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 H2 production rate of 339.3 μmol⋅g−1⋅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.