Conductive Black Titania Nanomaterials for Efficient Photocatalytic Degradation of Organic Pollutants

Abstract

Abstract: Titanium dioxide (TiO2) as an important semiconductor is widely used in the fields of solar cell, solar thermal collectors, and photocatalysis, but the visible-light power harvest remains insufficient due to the little effective visible-light absorption and many carrier-recombination centers originating from the wide band gap structure. Herein, conductive black titania (BT) nanomaterials with crystalline-TiO2-core/amorphous-TiO2−x-shell structure prepared through two-zone Al-reduction route are found efficient in photocatalyzing the degradation of organic pollutants to environmentally friendly products under full solar and even visible light irradiation. The unique core–shell structure and numerous surface oxygen vacancies or Ti3+ species in the amorphous layer accompanying prominent physicochemical properties of narrow band gap, high carrier concentration, high electron mobility, and excellent separation and transportation of photoinduced e−−h+ pairs result in exceptional photocatalytic efficiency. The optimized BT-500 (pristine TiO2 treated at 500 °C during two-zone Al-reduction process) catalyst achieves superior photocatalytic degradation rates for toluene and ethyl acetate as well as an excellent photostability with high degradation efficiency of 93% for the 6th reuse. Graphic Abstract: [Figure not available: see fulltext.]