Herein, we report a simple approach to synthesize high-performance and structurally stable CuO nanoparticles catalyst embedded in TiO₂ nanotube arrays for CO₂ reduction. To summarize, anodic TiO₂ nanotube arrays (TNTs) were electrochemical reductive doped in 1 mol/L (NH₄)₂SO₄ solution to form an activated surface. Then CuO nanoparticles were successfully filled into the pores pace of TNTs by electrodeposition and heat treatment. The effects of Ti(Ⅲ) reduction doping were discussed by means of electrochemical impedance spectroscopy (EIS) and X ray photoelectron spectroscopy (XPS). Results show that partial Ti(Ⅳ) in TNTs can be reduced to Ti(Ⅲ) by electrochemical reduction, which leads to a significant improvement in TNTs surfactivity and then benefits the deposition of Cu nanoparticles to form a stable embedded structure. As a consequence, the composite electrodes showed higher photoelectrocatalytic performance for CO₂ reduction. The maximum current of CuO-TNTs composite electrodes is up to −1.37 mA/cm² at −0.5 V and high selectivity for methanol synthesis is also obtained in this case. At the same time, the amount of methanol produced by the CuO/self-doped TNTs composite electrode is about 15% higher than that by the CuO/TNTs electrode without reductive doping.

在本文中，我们报告了一种简单的方法来合成嵌入TiO ₂纳米管阵列中的高性能且结构稳定的CuO纳米颗粒催化剂，以减少CO ₂。总之，将阳极TiO ₂纳米管阵列（TNT）电化学还原掺杂在1 mol / L（NH ₄）₂ SO _4中。溶液形成活化的表面。然后通过电沉积和热处理将CuO纳米颗粒成功填充到TNT的孔道中。通过电化学阻抗谱（EIS）和X射线光电子能谱（XPS）讨论了Ti（Ⅲ）还原掺杂的影响。结果表明，通过电化学还原可将TNTs中的部分Ti（Ⅳ）还原为Ti（Ⅲ），从而显着提高TNTs的表面活性，进而有利于Cu纳米颗粒的沉积，形成稳定的嵌入结构。结果，复合电极对CO ₂还原显示出更高的光电催化性能。CuO-TNTs复合电极的最大电流高达−1.37 mA / cm ²在-0.5V下，在这种情况下也获得了对甲醇合成的高选择性。同时，由CuO /自掺杂TNTs复合电极产生的甲醇量比没有还原掺杂的CuO / TNTs电极高约15％。