阳极的析氧反应(OER)是限制电解水制氢的主要因素,传统的OER电催化剂由于活性低、稳定性差等缺点无法实现大规模使用。过渡金属氧化物Co3O4是一种很有前景的OER催化剂,但较弱的导电性仍然制约着其电催化性能。通过对Co3O4进行改性以增强电催化活性及稳定性,分别在NaBH4和VCl3水溶液中两步浸泡法合成了富氧空位、V掺杂的Co3O4催化剂。利用XRD、SEM、EDS、TEM、HRTEM、SAED、拉曼光谱、XPS等手段对催化剂的相纯度、晶体结构、微观形貌、含有的官能团及化学键等性质进行测试和分析,并对催化剂进行电化学性能测试。结果表明:氧空位的引入使晶格间距有所增大,V成功掺杂到了Vo-Co3O4/NF(Vo指氧空位)结构中;氧空位和V掺杂协同提高了Co3O4/NF的OER性能。在1mol/LKOH中,V-Vo-Co3O4/NF仅需253mV/270mV的过电位就能驱动50(mA·cm-2)/100(mA·cm-2)的电流密度,Tafel斜率为71.5mV/dec,并具有100h的稳定性。其性能的提升主要归因于V掺杂及氧空位的引入对Co3O4电子构型的调控,低结晶度的表面暴露了更多活性位点,以及亲水性的增强有利于OER过程中反应中间体的吸附和解吸。

Oxygen evolution reaction (OER) at the anode is the main limiting factor for hydrogen production from electrolytic water, and conventional OER electrocatalysts cannot be re-alized for large-scale utilization due to the drawbacks of low activity and poor stability. The tran-sition metal oxide Co3O4 is a promising OER catalyst, but the weaker electrical conductivity re-stricts its electrocatalytic performance. In this study, the oxygen vacancy-rich, V-doped Co3O4 catalysts were synthesized by a two-step immersion method in NaBH4 and VCl3 aqueous solutions respectively, modifying Co3O4 to enhance the electrocatalytic activity and stability. The catalyst phrase purity, crystal structure, microstructure, frunctional group and chemical bond et al were detected and analyzed by XRD, SEM, EDS, TEM, HRTEM, SAED, Roman spectra, XPS and so on. The results show that the introduction of oxygen vacancies enlarges the lattice spacing and V is adulterated to Vo-CO3O4; oxygen vacancies and V doping synergistically improve the OER performance of Co3O4/NF. V-Vo-Co3O4/NF requires only 253 mV/270 mV overpotentials to drive a current density of 50(mA·cm-2)/100(mA·cm-2) in 1 mol/L KOH, with a Tafel slope of 71.5 mV/dec and 100 h stability. The enhanced performance is mainly attributed to the modu-lation of the electronic configuration of Co3O4 by V doping and the introduction of oxygen vacan-cies, the exposure of more active sites on the low crystallinity surface, and the enhancement of hydrophilicity that facilitates the adsorption and desorption of the reaction intermediates during the OER process.