Controlled Synthesis of Copper-Decorated H₂Ti₃O₇ Nanowires for 4-Nitrophenol Reduction and CO Oxidation

The growing demand for petroleum and its derivatives is the main contributor to increased carbon monoxide (CO) emissions. Catalytic oxidation is considered an effective technology for CO removal since it has low-energy consumption and pollution. There is great interest in reducing the costs associated with CO oxidation catalysts replacing noble metals (platinum and gold, for example) with non-noble transition metal oxides, such as titanium and manganese oxides. This work proposes a simple controlled synthesis of titanate nanowires decorated with copper islands prepared by a wet impregnation route using various copper quantities (1, 2.5, and 5 wt %). The nanomaterials were characterized by X-ray diffraction, small angle X-ray scattering, nitrogen physisorption (BET and BJH), transmission electron microscopy, and scanning electron microscopy. The copper/titanate materials with 5% copper allowed the CO oxidation at 100 °C, a very low temperature for this reaction, and the hydrogenation of 4-nitrophenol by sodium borohydride with very good kinetics, indicating great potential for these and other catalytic reactions. The use of copper not only improved the catalytic efficiency but also met environmental sustainability objectives.