PHOTOELECTROCATALYTIC CONVERSION OF CO2 AND BIOGAS INTO PRODUCTS OF ENERGY INTEREST USING Ti/TiO2 NANOSTRUCTURED SEMICONDUCTORS MODIFIED WITH COPPER

This work describes the superficial modification of Ti/TiO2 nanotubes by copper oxide electrochemical deposition, in different temperatures (25 and 65 ºC), and its application on the photoelectrocatalytic conversion of CO2 and biogas in products of energy interest. The different temperatures deposition resulted in the formation of different geometric forms on the surface of Ti/TiO2 nanotubes and in different photoelectrocatalytic activities. The photoelectrocatalytic conversion in 0.1 mol L-1 Na2SO4 with application of -0.1 V and UV irradiation resulted in the formation of acetone and methanol from CO2 and acetone and ethanol from biogas, being that the acetone production was higher for the semiconductor synthesized at 65 ºC, while the methanol and ethanol production was higher for the semiconductor at 25 ºC. The different characteristics observed, as well as the preferential formation of different products of photoelectrocatalytic reactions for semiconductors synthesized with different electrochemical deposition temperatures are discussed.

本研究阐述了采用氧化铜电化学沉积法对钛/二氧化钛（Ti/TiO₂）纳米管进行表面改性的工艺，沉积温度分别设置为25 ℃与65 ℃，并探究了该改性材料在CO₂与沼气光电催化制备能源相关产物中的应用。不同沉积温度会在钛/二氧化钛纳米管表面形成各异的几何形貌，同时赋予材料差异化的光电催化活性。在施加-0.1 V偏压、紫外辐照的0.1 mol/L硫酸钠电解液体系中进行光电催化转化时，CO₂可被转化为丙酮与甲醇，沼气则可被转化为丙酮与乙醇；其中，65 ℃下合成的半导体材料丙酮产率更高，而25 ℃下合成的样品甲醇与乙醇产率更具优势。本研究还对不同沉积温度制备的半导体所呈现的差异化特性，以及其光电催化反应的优势产物生成规律进行了讨论。