建構g-C3N4/WS2異質結陰極載體於光輔助電化學催化之特性研究

Performance of g-C3N4/WS2 Heterojunction Composite Cathodes in Photo-assisted Electrochemical System

光輔助電-芬頓系統形成光電協同催化效應，促進活性氧物種（ROS）生成以淨化汙廢水，其拓展至燃料電池應用可建構系統自保持（Self-operation Mechanism）機制。石墨相氮化碳（g-C3N4）二維材料展現良好紫外光與可見光之吸收響應；惟單一使用g-C3N4將面臨光生電荷易再結合及活性點位不足劣勢。本研究採用水熱法耦合g-C3N4與二硫化鎢（Tungsten disulfide，WS2）形成異質結（Heterojunction），接續以電泳沉積法將其鍍著於石墨氈（Carbon felt，CF）基材（g-C3N4／WS2／CF），進而研析異質結耦合比例對陰極系統催化之效益提升。顯示，g-C3N4／WS2／CF複合陰極以調配比例CNW1.0其電活性面積可達170.46 cm2較CF基材提升5倍，同時可有效延緩光生電荷再結合。於場域性能部分，CNW1.0獲得最高催化效率達92.4%，為CF基材1.82倍，並於批次試驗中展現良好之催化穩定性，其可歸因於g-C3N4與WS2構成2D／2D異質結，以此建構良好之光電協同催化機能。

The photo-assisted electro-Fenton system induces a synergistic catalysis effect by photoelectric processes, improving the generation of reactive oxygen species (ROS) for wastewater purification. When applied for fuel cell applications, it can create a self-operating mechanism. Graphitic carbon nitride (g-C3N4), a type of two-dimensional material, exhibits a favourable absorption response to both ultraviolet and visible light. Nonetheless, the use of g-C3N4 alone brings about challenges, including a tendency for a rapid recombination of photogenerated charges and a lack of sufficient active sites. This study utilizes a hydrothermal method to couple g-C3N4 with tungsten disulfide (WS2) to form a heterojunction, followed by electrophoretic deposition to coat it onto a carbon felt (CF) substrate (g-C3N4/WS2/CF). The CNW1.0 composite cathode exhibited an excellent catalytic efficiency of 92.4%, which is 1.82 times higher than that of the CF substrate, and excellent catalytic stability in batch tests for the field performance. This is attributed to the formation of the 2D/2D heterojunction between g-C3N4 and WS2, leading to an excellent photoelectric synergistic catalytic function.