MoS_(2)/GQDs催化剂的制备及微生物电解池的产氢性能研究  

Preparation and Electrochemical Evaluation of MoS_(2)/Graphene Quantum Dots as a Catalyst for Hydrogen Evolution in Microbial Electrolysis Cell

作　　者：代红艳[1] 杨慧敏[2] 刘宪 宋秀丽[3] 梁镇海[2] Hong-Yan Dai;Hui-Min Yang;Xian Liu;Xiu-Li Song;Zhen-Hai Liang(Department of Materials and Chemical Engineering,Taiyuan College,Taiyuan 030032,Shanxi,China;College of Chemistry and Chemical Engineering,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China;Department of Chemistry,Taiyuan Normal University,Taiyuan 030031,Shanxi,China)

机构地区：[1]太原学院材料与化学工程系,山西太原030032 [2]太原理工大学化学化工学院,山西太原030024 [3]太原师范学院化学系,山西太原030031

出　　处：《电化学》2021年第4期429-438,共10页Journal of Electrochemistry

基　　金：山西省高等学校科技创新计划项目(No.2019L1006);国家自然科学基金项目(No.51703151)资助.

摘　　要：通过水热法合成了一系列MoS_(2)/GQDs复合材料,并制成碳基复合电极。利用电化学测试手段挑选出最佳电极后用于微生物电解池(MEC)阴极的产氢性能研究。实验结果显示:Na_(2)MoO_(4)、半胱氨酸和GQDs的最佳原料配比为375:600:1,制备出的MoS_(2)/GQDs呈现明显的爆米花样纳米片结构,片层厚度在10 nm左右,当碳纸负载量为1.5 mg·cm^(-2)时,MoS_(2)/GQDs碳纸电极的析氢催化能力最佳。在MEC产氢实验中,MoS_(2)/GQDs阴极MEC的产气量、氢气产率、库仑效率、整体氢气回收率、阴极氢气回收率、电能回收率和整体能量回收率分别为51.15±3.15 mL·cycle^(-1)、0.401±0.032 m^(3)H_(2)·m^(3)d^(-1)、91.16±0.054%、66.64±5.39%、72.44±2.60%、217.26±7.42%和77.37±1.50%,均略高于Pt/C阴极MEC或与之媲美。另外,MoS_(2)/GQDs具有良好的长期稳定性,且价格便宜,有利于实际应用。Microbial electrolysis cell(MEC)is a relatively new bioelectrochemical technology that produces H2 and meanwhile treats organic wastewater.Cathode hydrogen evolution catalyst plays a key role in MEC.The doping of Graphene Quantum Dots(GQDs)into MoS_(2)nanosheets can improve the catalytic activity of MoS_(2)by creating abundant defect sites both in the edge plane and the basal plane,as well as enhancing the electrical conductivity.In this paper,using Na_(2)MoO_(4),cysteine and GQDs as raw materials,a series of MoS_(2)/GQDs composites were firstly synthesized via hydrothermal method,and then loaded on the carbon-based electrode.The optimal electrode was selected by electrochemical testing methods and used as a cathode of MEC to research the hydrogen production capacity.SEM image showed that the MoS_(2)/GQDs composite exhibited a popcorn-like nanosheet structure and the thickness of each nanosheet was about 10 nm.The specific surface area of MoS_(2)/GQDS composite reached 67.155 m^(2)·g^(-1),which was 16 times of the specific surface area of MoS_(2)(4.197 m^(2)·g^(-1)).TEM image showed that some lattice fringes representing GQDs were intermixed with lattice fringes representing MoS_(2),which indicated that GQDs were well embedded in MoS_(2).EDS results showed that the MoS_(2)/GQDS composite contained Mo,S,C and O,and the atomic ratio of Mo:S:C:O=1:2.5:1.9:1.2,indicating that the majority of Mo and S in the composite existed in the form of MoS_(2),while a part of S existed in the form of SO_(x).The LSV data of MoS_(2)/GQDs carbon paper electrode showed that the synthesized MoS_(2)/GQDs composite(2#)had the best catalytic activity toward hydrogen evolution when the raw material ratio of Na_(2)MoO_(4),cysteine and GQDs was 375:600:1 with the optimum load of 1.5 mg·cm^(-2).The Tafel slope of MoS_(2)/GQDs electrode(2#,1.5 mg·cm^(-2))was found to be 44.3 mV·dec^(-1),lower than that of pure MoS_(2)electrode,which indicated that the doping of GQDs into MoS_(2)nanosheets made the electron transport more efficiently and

关 键 词：MoS_(2)/GQDs 碳基电极 微生物电解池 产氢 

分 类 号：TQ116.2[化学工程—无机化工] TQ426