Hydrothermally Treating High-Ti Cinder for a Near Full-Sunlight-Driven Photocatalyst toward Highly Efficient H2 Evolution

Abstract

A major drawback of conventional photocatalysts like TiO2 is the limit of only working under ultraviolet irradiation. As a solution, visible-light-driven photocatalysts have been explored in recent years but full-sunlight-driven photocatalysts are still lacking. Herein, multielement-codoped (Mn, Fe, Si, Al, S, F, etc.) TiO2 nanomaterials were prepared from an industrial high-Ti cinder (HiTi) by a two-step hydrothermal method using NaOH and NH4F (or H2O) as morphology controlling agents. The prepared HiTi photocatalyst exhibits a strong absorption at near full-sunlight spectrum (300–800 nm). Among all TiO2-based photocatalysts without any noble metal cocatalyst, the photocatalytic H2 evolution rate on NaOH- and H2O-hydrothermally treated HiTi (HiTi-TiO2) is remarkably superior to the reference P25 TiO2 powders by a factor of 3.8 and thus is the highest. However, NaOH- and NH4F-treated HiTi (HiTi-TiO2-F) shows a lower photoreactivity than HiTi-TiO2 does. Mechanistic studies show that the multielement-doped ...