Facile solvothermal synthesis of nitrogen-doped SnO2 nanorods towards enhanced photocatalysis

Abstract

Heteroatom doping has proved to be one of the most effective approaches to further improve the photocatalytic activities of semiconducting oxides originating from the modulation of their electronic structures. Herein, nitrogen-doped SnO2 nanorods were synthesized via facile solvothermal processes using polyvinylpyrrolidone (PVP) as a dispersing agent and ammonium water as the N source, respectively. Compared with pure SnO2 sample, the as-synthesized nitrogen-doped SnO2 nanorods demonstrated enhanced photocatalytic performances, evaluated by the degradation of rhodamine B (RhB), revealing the effectiveness of nitrogen doping towards photocatalysis. In particular, the optimal photocatalyst (using 0.6 g PVP and 1 mL ammonia water) could achieve up to 86.23% pollutant removal efficiency under ultraviolet (UV) light irradiation within 150 min, showing 17.78% higher efficiency than pure SnO2. Detailed structural and spectroscopic characterization reveals the origin of activity enhancement of nitrogen-doping SnO2 in contrast with pure SnO2. Specifically, the bandgap and the morphologies of nitrogen-doped SnO2 have changed with more chemisorbed sites, which is supposed to result in the enhancement of photocatalytic efficiency. Moreover, the possible formation mechanism of nitrogen-doped SnO2 nanorods was discussed, in which PVP played a crucial role as the structure orientator.