Si NWs/GQDs复合结构的设计及其光电催化性能

采用金属催化化学蚀刻法制备硅纳米线阵列（silicon nanowire arrays，Si NWs），通过高速旋涂仪将自上而下法制备的石墨烯量子点（graphene quantum dots, GQDs）负载到Si NWs上。X射线光电子能谱（X-ray photoelectron spectroscopy, XPS）等表征结果证明，GQDs能够通过高速旋涂仪负载到Si NWs上。扫描电子显微镜（scanning electron microscopy, SEM）形貌观测结果表明，蚀刻时间与Si NWs纳米线长度成正比。光电化学测试结果表明，性能最优的蚀刻时间为45 min。与原始硅片相比，GQDs负载的Si NWs光电密度达到了0.95 mA/cm²，性能提升了30多倍。电化学交流阻抗（electrochemical impedance spectroscopy, EIS）测试结果表明：GQDs的加入能显著提升载流子的传输效率。紫外–可见漫反射光谱（ultravioletray-visible diffuse reflectance spectroscopy, UV-Vis DRS）结果显示负载GQDs可以有效提升Si NWs对光的吸收效果。

Design of Si NWs/GQDs Composite Structure and Its Photoelectrocatalytic Performance

Silicon nanowire arrays (Si NWs) were prepared by metal-catalyzed chemical etching method, and the graphene quantum dots (GQDs) prepared by the top-down method were loaded onto Si NWs by a high-speed spin coater. X-ray photoelectron spectroscopy (XPS) and other characterization methods prove that the GQDs can be loaded onto Si NWs through a high-speed spin coater. Scanning electron microscope (SEM) morphology observation results show that the etching time is proportional to the length of Si NWs nanowires. The photoelectrochemical test results show that the optimal etching time is 45 min. Compared with the plane silicon wafers, the photoncurrent density of GQDs-loaded Si NWs is up to 0.95 mA/cm², and the performance is improved by more than 30 times. Electrochemical impedance spectroscopy (EIS) results show that the addition of GQDs can significantly improve the carrier transmission efficiency of Si NWs. ultravioletray-visible diffuse reflectance spectroscopy (UV-Vis DRS) results show that the light absorption of the Si NWs can be improved by loading GQDs.