In-situ photodeposition of co-catalyst Ni_(2)P on CdS for photocatalytic conversion of ethanol for synergistic hydrogen production

CdS上原位光沉积助催化剂Ni_(2)P用于光催化转化乙醇协同产氢

In this study,Ni_(2)P/CdS composites were constructed by depositing non-precious metal co-catalyst Ni_(2)P on a one-dimensional network of CdS using a simple in-situ photodeposition method.The prepared photocatalysts promoted the decomposition of ethanol into high-value-added products while generating hydrogen.The composite photoanodes loaded with the Ni_(2)P co-catalysts showed significantly higher ethanol conversion and hydrogen production in the visible light region,which was almost three times higher than that of pure CdS.The main products of photocatalytic ethanol production are acetaldehyde(AA)and 2,3-butanediol(2,3-BDA).Compared with CdS,the selectivity of the composite photocatalysts for converting ethanol to acetaldehyde was significantly improved(62% to 78%).Characterization of the prepared photocatalysts confirmed that the loading of Ni_(2)P co-catalysts on CdS not only broadened the optical region of the catalysts for trapping light but also effectively promoted the separation and transfer of charge carriers,which significantly improved the photocatalytic efficiency of ethanol conversion and hydrogen production in the catalysts.It has been proven through Electron Paramagnetic Resonance testing that loading a Ni_(2)P co-catalyst on CdS is beneficial for the adsorption of hydroxyethyl radicals(*CH(OH)CH_(3)),thereby further improving the selectivity of acetaldehyde.This study plays an important role in the rational design of composite catalyst structures and the introduction of co-catalysts to improve catalyst performance,promote green chemistry,advocate a low-carbon society,and promote sustainable development.

本工作采用简单的原位光沉积法,在一维网络CdS上沉积非贵金属助催化剂Ni_(2)P,从而构建了Ni_(2)P/CdS复合材料。所制备的光催化剂能够促进乙醇分解成高附加值产品同时产生氢气。负载Ni_(2)P助催化剂后的复合光阳极在可见光区的乙醇转化率和产氢率显著提高,是纯CdS的3倍。且光催化乙醇的主要产物为乙醛和2,3-丁二醇,与CdS相比复合光阳极将乙醇转化为乙醛的选择性有了显著提高(62%至78%)。对制备的光催化剂进行的各种表征证实,在CdS上负载Ni_(2)P助催化剂不仅拓宽了催化剂捕获光的光学区域,还有效促进了电荷载流子的分离和转移,从而显著提高了催化剂中乙醇转化和制氢的光催化效率。通过电子顺磁共振测试证明,在CdS上负载Ni_(2)P助催化剂有利于羟乙基自由基(*CH(OH)CH_(3))的吸附,从而进一步提高乙醛的选择性。本研究对合理设计复合催化剂结构和引入助催化剂以提高催化剂性能,推进绿色化学发展,倡导低碳社会,促进可持续发展具有重要作用。