TiO2基光催化材料是太阳能光催化/光电化学水解制氢领域中研究最早、使用最广泛、最重要的材料之一.经由氢气(H2)、氨气(NH3)单独或共同热处理,来窄化TiO2的光学带隙的研究工作也较多,但多数工作局限于常规温度短时间(500℃/1 h)退火.对于从(500℃/5 h)常规时常,直到相对较高温度较长时常(900℃/9 h)的条件下,TiO2基材料的价带边演化情况的研究,还少见报道.本文以水热生长在碳布(Carbon Cloth/C)上TiO2纳米棒阵列(TiO2NRAs)为研究对象,经由常规(500℃/5 h)到相对极限条件(900℃/9 h)下,H2/NH3单独热处理以及顺次热处理后,系统研究了材料的价带边的演化情况.结果表明,随着热处理温度升高,时间加长,材料表面顺次出现了TiOxNy类三元化合物及TixNy,价带边向真空能级出现明显蓝移.这对进一步了解N掺杂TiO2基纳米材料的光催化/光电化学过程的机制问题将提供有益的帮助和启发.
Titanium Dioxide(TiO2) is one of the most studied and widespread application for solar energy photocatalytic or photoelectrochemical water splitting H2 generation. Works for narrowing TiO2 optical band gap,via H2,NH3 solo-or co-thermal treatment,have been done a lot. But few works have been reported to address the evolution process of TiO2 valance band edge when thermal treatment from 500 ℃/5 h to 900 ℃/9 h.Here,we annealing TiO2 Nano Rod Arrays(TiO2 NRAs) which hydrothermal grown on Carbon Cloth in H2 or/and NH3 atmosphere sequentially. And the evolution process of TiO2 NRAs was investigated systematically.Ternary compounds formed on the surface of TiO2 NRs with increased calcination temperature and prolonging the reaction time,and the valance band edge of which blue shifts to the vacuum. Our work should do some favor for understanding the mechanism of N-doped TiO2 during photocatalytic or photoelectrochemical water splitting process.