钒掺杂对SrTiO3光学性质及光催化性能的影响
Effect of doping vanadium on optical and photocatalytic properties of SrTiO3

采用水热法合成了掺钒量分别为0 mol%、0.5 mol%、1.0 mol%的SrTiO3（编号依次为S-0、S-0.5、S-1.0），通过XRD、SEM、BET比表面积分析、电子顺磁共振谱（EPR）、XPS、FTIR、UV-vis吸收光谱及PL等方法测试了材料的结构特征及光学性质，并采用NO光催化氧化及CO2光催化还原对比了掺钒前后SrTiO3的光催化活性的变化。研究结果表明，钒对SrTiO3中的Ti位进行取代掺杂；掺钒导致SrTiO3的可见光响应增强，氧空位减少；掺钒量为0.5 mol%的S-0.5比未掺钒的S-0在反应初期具有更好的光催化效果，但在反应后期S-0.5的催化活性衰减较快。综合结果显示，氧空位是光催化还原CO2反应过程中的重要活性位点，掺钒后氧空位减少导致活性位点不足是光催化反应后期掺钒SrTiO3材料活性衰减的主要原因。 Pure SrTiO3, 0.5 mol% and 1.0 mol% vanadium doped SrTiO3 were synthesized through hydrothermal method (Noted as S-0, S-0.5, S-1.0 successively). Characterizations including XRD、SEM、BET specific surface area analysis、electron paramagnetic resonance(EPR)、XPS、FTIR、UV-vis absorption spectra and PL offered information about structural features and optical properties of as-prepared catalysts. NO photo-oxidation reaction and CO2 photoreduction reaction were employed to evaluate the photocatalytic activity of the catalysts. As the study results reveale, the visible-light response improves, and the density of oxygen vacancy decreases as vanadium was doped into Ti-site; S-0.5, the SrTiO3 sample with 0.5 mol% vanadium doping, shows a better catalytic activity than S-0 at the preliminary stage, but its catalytic activity decays subsequently. According to the characterizations and tests, it could be speculated that oxygen vacancy is the active site for the CO2 photoreduction reaction, and the insufficient of active sites resulting from the decrease of oxygen vacancy after vanadium doping is the key reason for the decay of photocatalytic activity. 国家自然科学基金（21473248