电化学制备超细g-C_(3)N_(4)量子点及其电催化析氢性能  

Electrochemical fabrication of ultrafine g-C_(3)N_(4) quantum dots as a catalyst for the hydrogen evolution reaction

作　　者：杨娜娜 陈志刚[1] 赵志刚[1,2] 崔义[1,2] YANG Na-na;CHEN Zhi-gang;ZHAO Zhi-gang;CUI Yi(School of Nano-Tech and Nano-Bionics,University of Science and Technology of China,Hefei 230026,China;Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou 215123,China)

机构地区：[1]中国科学技术大学纳米技术与纳米仿生学院,安徽合肥230026 [2]中国科学院苏州纳米技术与纳米仿生研究所,江苏苏州215123

出　　处：《新型炭材料》2022年第2期392-401,共10页New Carbon Materials

基　　金：国家自然科学基金(91845109,21872169,22109171,22172190);中科院稳定支持基础研究领域青年团队计划(YSBR-022),中科院青年交叉团队项目(JCTD-2021-14),江苏省博士后科研资助计划项目(2021K226B).

摘　　要：由于其高含量的面内氮元素、优异的化学和热力学稳定性、可调的电子能带结构和环境友好的特点,石墨相结构的氮化碳(g-C_(3)N_(4))材料作为一种非金属催化剂在光电催化领域已引起广泛关注。相较于光催化领域能带结构的调控,gC_(3)N_(4)在电催化领域的设计主要集中在活性位点的构筑和电子转移能力的调节。本文报道了一种三价Al^(3+)离子电化学插层超快制备超细g-C_(3)N_(4)量子点(QDs)的剥离策略,与传统的碱金属离子相比,Al^(3+)带电荷量大、冲击能力强,易于得到粒径和厚度更小的均一量子点材料。相应的透射电镜(TEM),原子力显微镜(AFM)和紫外吸收光谱仪(UV-vis)表征证实了所制g-C_(3)N_(4) QDs的平均粒径只有3.5 nm,厚度只有3个C―N原子层(~1 nm),并且富含C/N缺陷。这种超细且富含缺陷的量子点材料在0.5 mol L^(-1)H_(2)SO_(4)电解液中具有接近0 V的电催化析氢(HER)开口电位、优异的过电位(η_(10)=208 mV)和较低的塔菲尔斜率(b=52 mV·dec^(-1))。这项工作提出的快速制备富含C/N缺陷g-C_(3)N_(4) QDs的策略也为研究其它二维层状材料的剥离及其在电催化领域的应用提供了一条有趣的研究思路,有利于发掘二维材料更多丰富的物化性质。Because of its high concentration of in-plane elemental nitrogen,superior chemical/thermal stability,tunable electronic band structure and environmentally friendly nature,graphite-like carbon nitride(g-C_(3)N_(4))is a new promising metal-free material that has drawn much attention in photo-/electric catalysis.Compared with the regulation of the band structure in photocatalysis,the deliberate synthesis of g-C_(3)N_(4) electrocatalysts is mainly focused on the construction of catalytic sites and the modulation of the charge transfer kinetics.This work reports a rapid method for synthesizing ultrafine g-C_(3)N_(4) quantum dots(QDs)by electrochemical exfoliation using Al^(3+)ions as an intercalation agent.Uniform g-C_(3)N_(4) QDs with small lateral size and thickness were collected more easily due to the higher charge density and stronger electrostatic force of Al^(3+)ions in the lattice of the host material,compared to conventional univalent alkali cations.The QDs had an average lateral dimension and thickness of 3.5 nm and 1.0 nm,respectively,as determined by TEM and AFM measurements.The presence of a large number of C/N defects was verified by the UV-vis spectra.The ultrafine g-C_(3)N_(4) QDs had a superior hydrogen evolution reaction performance with an ultra-low onset-potential approaching 0 V,and a low overpotential of 208 mV at 10 mA cm^(-2),as well as a remarkably low Tafel slope(52 mV·dec^(-1))in an acidic electrolyte.

关 键 词：g-C_(3)N_(4) 电化学剥离 Al^(3+)离子 量子点 电催化析氢 

分 类 号：TQ127.1[化学工程—无机化工]