利用鎢磷硫化物奈米片進行高效光電化學產氫反應研究

Highly Efficient of Photoelectrochemical Hydrogen Generation Reaction Using Tungsten Phosphosulfide Nano-sheets

余欣縉(Yu Hsin-Chin)

指導教授 ： 胡淑芬

國立臺灣師範大學/理學院/物理學系/碩士(2018年)

https://doi.org/10.6345/THE.NTNU.DP.015.2018.B04

摘要

本研究以矽晶圓為光催化水分解之基板，因其具光電流轉換特性與合適之能帶位置，故適合作為光陰極材料。光電化學系統以太陽光產氫作為解決當代能源需求問題之重要策略。於此策略，白金與其他貴金屬展現良好之光電流特性，但其價格昂貴，故開發地球上豐富之非貴金屬催化劑具其必要性。
　　本研究以濕式蝕刻法將矽晶圓表面改質，使其表面呈微米金字塔形貌，因表面粗糙度增加，進而提升光吸收效率。以滴落塗佈法(drop-casting)於矽微米金字塔表面進行共催化劑之修飾，降低矽基板之光生載子動能不足之問題，有效提高產氫效率。此外，藉由熱退火技術於矽微米金字塔表面成功以鎢磷硫化物奈米片修飾，觀察其太陽能驅動之產氫反應活性。以二硫化鎢作為共催化劑之基材，發現其於RHE 0 V之光電流密度為-5.80 mA/cm2，爾後更進一步探討摻雜磷對於二硫化鎢之影響，發現於奈米結構中之磷摻雜可有效使二硫化鎢裸露更多活性點，使反應更加活躍，於RHE 0 V之光電流密度為 -19.11 mA/cm2，並具較低之Tafel斜率。藉電化學量測結果再次驗證WS0.60P1.40@Si MPs具最佳電流密度與電雙層特性。於8小時內具非常穩定之電流響應。此效應可藉由摻雜磷後之樣品光電化學活性與電化學活性提升加以證實。

關鍵字

光催化水分解 ； 二硫化鎢 ； 產氫反應

並列摘要

In this study, a silicon wafer is used as a substrate for photocatalytic water splitting. Because of its effective photocurrent conversion characteristics and suitable energy band gap, it is suitable for a photocathode material. Hydrogen produced from sunlight by photoelectrochemical systems is an important strategy to solve the problem of contemporary energy demand. In this strategy, platinum and other precious metals exhibit very good photocurrent characteristics, but their prices are too expensive, so the necessity of developing abundant non-precious metal catalysts on the earth is very important.
　　In this study, the wet etching process was used to modify the surface of the silicon wafer to form a micro-pyramidal surface, which made its surface rough and increased the light absorption efficiency. The co-catalyst is modified by drop-casting on the surface of the micro-pyramid silicon, thereby reducing the problem of the poor kinetics of photoinduced carriers of the Si substrate and effectively activating the hydrogen production reaction. By using the thermal annealing technique, we successfully modified the surface of micro-pyramidal silicon with tungsten phosphosulfide nanosheets. And demonstrated the activity of hydrogen evolution reaction. Using tungsten disulfide as a co-catalyst, it was found that RHE 0 V exhibited a photocurrent density of -5.80 mA/cm2. Afterward, the effect of phosphorus doping on tungsten disulfide was further explored, and phosphorus doping was found in the nanostructure. The miscibility can effectively expose tungsten disulfide to more active sites and make the reaction more active. The photocurrent density at RHE 0 V is -19.11 mA/cm2 and the Tafel slope is lower. The results of electrochemical measurements verified that WS0.60P1.40@Si MPs have the best current density and electrical double layer properties. It has a very stable current response over than 8 hours. The raising activity by phosphorous doping confirms that photoelectrochemical activity and electrochemical activity can be increased by phosphorous doping.

並列關鍵字

Solar Water Splitting ； Tungsten disulfide ； Hydrogen Evolution Reaction

參考文獻

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