Z型Cu2O-(rGO-TiO2)光催化剂的制备及其对甲基橙的降解性能

通过简易的三步合成法成功制备出在日光下对甲基橙(MO)具有良好光催化性能的Z型Cu₂O-(rGO-TiO₂)光催化剂.与传统二元异质结不同，还原氧化石墨烯(rGO)作为中间介质可促进光催化剂量子效率的提升，可提高Cu₂O-TiO₂的氧化还原能力.当rGO负载量(质量分数)为1%时，Cu₂O-(rGO-TiO₂)具有最佳的光催化活性.采用扫描电镜(SEM)、X射线衍射(XRD)、紫外-可见漫反射(UV-Vis DRS)研究光催化剂的形貌结构和光学性质，采用探针法和光致发光光谱(PL)分析并验证了Z型光催化体系. Cu₂O-(rGO-TiO₂)光催化剂厚度约32.24 μm，Cu₂O呈多面柱状结构，以{111}晶面(具有良好的光催化活性)为主，TiO₂纳米颗粒均匀分散在二维单层褶皱片状结构的rGO表面，Cu₂O、TiO₂和rGO组成了Z型光催化体系.分别探究不同光源和rGO负载量对光催化性能的影响.结果表明:在模拟太阳光照射条件下，中间介质rGO的存在提升了量子效率，增强了光催化剂性能，Cu₂O-(1%rGO-TiO₂)光照2 h对甲基橙的催化降解率为58%.该Z型光催化剂可被应用于染料废水的降解，研究结果为环境治理提供了新的技术发展思路.

The Preparation of Z-Scheme Cu2O-(rGO-TiO2) Photocatalyst and Its Performance in Methyl Orange Degradation

An effective Z-scheme Cu₂O-(rGO-TiO₂) photocatalyst was successfully synthesized via a simple three-step approach for Methyl Orange (MO) removal under sunlight irradiation. Unlike the traditional heterojunction model, reduced graphene oxide (rGO) serving as conjunction enhanced Cu₂O-TiO₂ redox ability by increasing quantum efficiency. When loaded with 1% (mass fraction) rGO, the Z-scheme Cu₂O-(rGO-TiO₂) exhibited the best photocatalytic activity. The morphologies and optical properties of photocatalysts were characterized with a field emission scanning electron microscope (SEM), X-ray diffraction (XRD) and ultraviolet-visible spectrophotometer (UV-Vis DRS). The mechanism of Z-scheme system was probed via photoluminescence (PL) spectrum. The results showed that the thickness of Cu₂O-(rGO-TiO₂) composite film was about 32.24 μm. Cu₂O had a multi-faceted columnar structure with {111} crystal planes, which showed excellent photocatalytic activity. TiO₂ nanoparticles were evenly distributed on the surface of rGO that had a two-dimensional mono-layer fold structure. Cu₂O, TiO₂ and rGO successfully formed a Z-scheme photocatalytic system. The effects of different light sources and rGO loadings on Cu₂O-TiO₂ were studied respectively. The results showed that under simulated sunlight, the presence of rGO intermediary promoted MO removal efficiency and enhanced photocatalyst performance. The removal efficiency of MO was up to 58% in 2 hours. The effective Z-scheme system can be used for dye wastewater degradation and provide new ideas for environmental management.