金属相二硫化钼催化剂的液相制备及其析氢性能研究

Liquid-phase preparation and hydrogen evolution performance of 1T-MoS_(2) catalyst

电解水产氢被认为是未来实现可持续、清洁能源供应的一种重要方式。为了实现这一目标,开发高效、廉价的电催化剂是至关重要的。二硫化钼(MoS_(2))是一种被认为可以替代贵金属的催化剂,其具有配位不饱和的边缘活性位点和接近铂(Pt)的氢吸附自由能。然而,由于半导体相(2H-MoS_(2))受限于自身的导电能力较差及活性位点数目较低,因此具有不同配位结构的金属相(1T-MoS_(2))被认为是更理想的电解水析氢材料,因为它表现出类似于金属的导电能力且能提供更多的催化活性位点。本研究通过简单的水热法和退火法,使用不同的酸性溶剂合成出了高达76%1T相占比的二硫化钼(MoS_(2)-A)。在电解水产氢实验中,MoS_(2)-A在0.5 mol/L的硫酸中表现出优异的电催化析氢性能,其在10 mA/cm^(2)处的过电位为324 mV,Tafel斜率为95 mV/dec。值得一提的是,在合成过程中添加了乙酸,可以在一定程度上减缓二硫化钼纳米片的团聚并促使其垂直排列,从而得到尺寸更小、能够暴露更多活性位点、具有优异电子传输能力的催化剂。这些发现表明,MoS_(2)-A在电催化析氢领域有很大的潜力,可以作为一种廉价、高效的电催化剂来降低电解水产氢的成本,并促进其商业化应用。

Electrolytic hydrogen production from water is considered an important way to achieve sustainable and clean energy supply in the future.To achieve this goal,the development of efficient and low-cost electrocatalysts is crucial.Molybdenum disulfide(MoS_(2))is a catalyst that is considered to be a substitute for precious metals due to its coordination unsaturated edge active sites,and research has shown that it has hydrogen adsorption free energy close to platinum(Pt).However,the semiconductor phase(2H-MoS_(2))is limited by its poor conductivity and low number of active sites.Therefore,the metallic phase(1T-MoS_(2))with different coordination structures is considered to be an ideal material for electrolytic hydrogen production because it exhibits conductivity similar to that of the metals and can provide more catalytic active sites.In this study,high proportion(up to 76%)of 1T phase MoS_(2)(MoS_(2)-A)were synthesized using simple hydrothermal and annealing methods with different acidic solvents.MoS_(2)-A demonstrated excellent electrocatalytic performance for hydrogen evolution in 0.5 mol/L sulfuric acid,with an overpotential of 324 mV at a current density of 10 mA/cm^(2) and a Tafel slope of 95 mV/dec.It is worth to mention that the addition of the acetic acid in the synthesis process could reduce the aggregation of molybdenum disulfide nanosheets and promote their vertical arrangement,resulting in a catalyst with smaller size,more exposed active sites and excellent electron transfer ability.These findings suggest that MoS_(2)-A has great potential in the field of electrocatalytic hydrogen evolution and could be used as a cheap and efficient electrocatalyst to reduce the cost of electrolytic hydrogen production and promote its commercial application.