凹凸棒石/g-C3N4复合材料的制备及其电催化析氧性能研究

以凹凸棒石(ATP)为载体, 通过原位沉积, 结合冷冻干燥、程序焙烧工艺在其表面负载不同质量分数的类石墨相氮化碳(g-C₃N₄)薄层材料, 制备系列ATP/g-C₃N₄复合材料用于电催化析氧反应, 产物标识为ATP/g-C₃N₄-w (质量分数w = mATP: (mATP + mg-C₃N₄)=0.33、0.40、0.50、0.67), 并研究在0.1 mol/L KOH的电解液中的电催化析氧性能。结果表明: g-C₃N₄薄层通过Si-O-C键牢固负载于凹凸棒石表面, 从而有效调变g-C₃N₄表面的电子层结构, 提供更多的催化活性位点。电催化析氧测试的结果表明: ATP/g-C₃N₄-0.50具有最优的析氧催化性能, 在10 mA/cm ²电流密度下其析氧过电位为410 mV, 塔菲尔斜率为118 mV/dec, 并表现出优异的析氧稳定性。

Attapulgite/g-C3N4 Composites: Synthesis and Electrocatalytic Oxygen Evolution Property

A novel kind of electrocatalytic oxygen evolution catalyst was fabricated by introducing g-C₃N₄ ultrathin films onto the surface of attapulgite (ATP) via a simple in-situ depositing technique, combined with freeze-drying and programmed roasting process. The obtained product was identified as ATP/g-C₃N₄. In order to achieve the best catalyst, a series of ATP/g-C₃N₄ composites with different mass fraction of ATP were obtained and marked as ATP/g-C₃N₄-w, where w represents the mass fraction of ATP (w =mATP: (mATP + mg-C₃N₄)= 0.33, 0.40, 0.50, 0.67). Results show that g-C₃N₄ thin layers are uniformly loaded onto the ATP surface via the chemical bond (Si-O-C), which is beneficial to tailor the surface electronic structure of g-C₃N₄ and provide more active sites. Their electrocatalytic oxygen evolution properties in 0.1 mol/L KOH were investigated. It is found that ATP/g-C₃N₄-0.50 presents the best oxygen evolution catalytic performance and has excellent oxygen evolution stability. Its oxygen evolution over potential is 410 mV and the Tafel slope is 118 mV/dec at a current density of 10 mA/cm ². The results suggest that ATP/ g-C₃N₄-0.50 can be used as a potential oxygen evolution catalyst.