School of Chemistry and Environmental Science, Shangrao Normal University
Department of Chemical Engineering, Taiyuan University of Technology

以MAX (Ti3AlC2)为原料，依次采用蚀刻、剥层的方法制备了MXene（Ti3C2Tx）及超薄层MXene纳米片（MXene nanosheets，MXene-NS，即Ti3C2Tx-NS）。通过扫描电子显微镜（Scanning Electron Microscope，SEM）、X射线衍射（X-Ray Diffraction，XRD）及X射线光电子能谱仪（X-Ray Photoelectron Spectroscopy，XPS）表征了MXene-NS的形貌、结构及组成。采用电化学方法对比了MAX、MXene以及MXene-NS的电催化析氢（Hydrogen Evolution Reaction, HER)性能。结果表明，与MAX和MXene相比，MXene-NS在1 mol/L KOH溶液中具有最低的过电位（190 mV @ −10 mA/cm2）、最小的塔菲尔斜率（168 mV/dec）、最小的电荷转移电阻以及最大的电活性面积。此外，在多电流阶跃下，MXene-NS也展示了良好的电位响应性。经过长周期的稳定性测试，MXene-NS的极化曲线并未出现明显衰减，显示了优异的析氢稳定性。这些结果表明，MXene的剥层可以有效提高材料的电催化性能，MXene-NS具有替代贵金属催化剂的潜质。

MXene (Ti3C2Tx) was prepared by etching MAX (Ti3AlC2) raw material and then ultrathin MXene nanosheets (MXene-NS, namely Ti3C2Tx-NS) was fabricated by using exfoliating method. The morphology, structure and elemental composition of the MXene-NS were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electrocatalytic hydrogen evolution reaction (HER) properties of MAX, MXene and MXene-NS were compared by electrochemical tests. The results revealed that compared with MAX and MXene, in 1 mol/L KOH, MXene-NS exhibited the lowest overpotential (190 mV@ −10 mA/cm2), the smallest Tafel slope (168 mV/dec), the smallest charge transfer resistance and the largest electrochemical active surface area. In addition, MXene-NS displayed a good potential response vs. current density. Furthermore, after long-term durability test, the polarization curve of MXene-NS was not notably decayed, which demonstrated the excellent stability for hydrogen evolution. All these results indicated that the exfoliation of MXene could effectively improve its electrocatalytic performance and the as-exfoliated MXene-NS was an excellent alternative for replacing the noble metal catalysts.

国家自然科学基金（22169017），江西省自然科学基金（20224BAB203026），上饶市研发投入后补助项目（SKB2021002），江西省教育厅项目（GJJ2201823，GJJ201709，GJJ201706，GJJ211709）和上饶市基础研究项目（2020L001，2021F009）资助

段小卉, 刘堰, 吴实, 陈熙, 杨言言, 余钟亮. 超薄MXene纳米片碱性电催化析氢反应性能[J]. 燃料化学学报（中英文）, 2023, 51(9): 1306-1312.

DUAN Xiao-hui, LIU Yan, WU Shi, CHEN Xi, YANG Yan-yan, YU Zhong-liang. Ultrathin MXene nanosheets for electrocatalytic hydrogen evolution under alkaline condition[J]. Journal of Fuel Chemistry and Technology, 2023, 51(9): 1306-1312.