本研究成功透過兩步法合成出CuS@C3N4與CuS@S0.3C3N4複合材料，此種複合材料包含高催化活性P型半導體硫化銅(Copper sulfide, CuS)和N型半導體石墨氮化碳材料(Graphic Carbon Nitride, g-C3N4)所形成P-N異質結構的CuS@C3N4。此種P-N異質結構會因為內部電場驅動力的提升，從而降低對電極/電解質界面的阻抗，促進電子從對電極傳輸到電解質，這將有助於量子點敏化太陽能電池(Quantum Dot Sensitized Solar Cells, QDSSCs)的效率提升。同時本研究也以異原子參雜方式在g-C3N4中調整其能帶結構，其中發現硫參雜g-C3N4 (S0.3C3N4) 可以具有較高的費米能階，電子便有利於從S0.3C3N4導帶轉移到CuS導帶，並且可由IPCE ( Incident Photon-to-current Conversion Efficiency )與OCVD (Open Circuit Voltage Decay )實驗中，說明CuS@S0.3C3N4異質結構能使電子快速填補電解液電洞，抑制光陽極電子被捕獲機率，加速電子注入效率，最終研發出CuS@S0.3C3N4複合材料對電極，其短路電流密度(JSC)由單純CuS條件對電極的26.8 mA·cm-2提升至29.3 mA·cm-2，光電轉換效率高達9.92%。
為了進一步說明CuS@ S0.3C3N4的複合材料，進行了相關材料的分析鑑定，透過HRTEM、SEM、XRD、XPS、EPR來進行奈米材料結構分析。此外為了驗證透過摻雜硫調節石墨氮化碳能帶結構，利用UV/可見光光譜與Mott-Schottky 來探討材料能帶結構；最後針對不同條件對電極進行CV、、Tafel、OCVD來說明整體材料電催化性。

In this study, We successfully synthesized CuS@C3N4 and CuS@S0.3C3N4 composite materials through a two-step method. This composite material contains high catalytic activity P-type semiconductor copper sulfide (CuS) and N-type Graphic Carbon Nitride (g-C3N4). This kind of P-N heterostructure will reduce the resistance to the electrode/electrolyte interface due to the increase of the driving force of the internal electric field, which will help improve the efficiency of quantum dot sensitized solar cells (QDSSCs). At the same time, this study also adjusted the energy band structure in g-C3N4 by means of heteroatom doping. It was found that sulfur-doped g-C3N4 (S0.3C3N4) can have a higher Fermi energy level, and the electrons are beneficial to transfer from S0.3C3N4 conduction band is to CuS conduction band, and It can be detected by IPCE (Incident Photon-to-current Conversion Efficiency) and OCVD (Open Circuit Voltage Decay) experiments, indicating that the CuS@ S0.3C3N4 heterostructure can make electrons quickly fill the electrolyte holes, inhibit the capture probability of photoanode electrons, and accelerate the electron injection efficiency. Finally, the counter electrode of CuS@ S0.3C3N4 composite material was developed, and its short-circuit current density (JSC) was increased from 26.8 mA cm-2 of the original condition CuS counter electrode to 29.3 mA cm-2, the photoelectric conversion efficiency is as high as 9.92%.

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