通过过氧化聚钨酸水热合成方法制备了不同晶体结构和表面形貌的WO₃，研究了pH对晶体结构和表面形貌的影响。结果表明，调节pH可以实现对WO₃晶型和形貌的可控合成；晶体结构对WO₃的可见光吸收能力有重要的影响；不同晶相WO₃的PEC性能差异明显，与六方WO₃（h-WO₃）和六方-立方WO₃（h-c-WO₃）的PEC性能相比，立方WO₃（c-WO₃）纳米棒的PEC性能得到极大地提高，主要是因为晶体结构改善了c-WO₃对长波长可见光的吸收能力；另外，在PEC水分解过程中，纳米棒加速了光生电子的转移速度，从而减小了电子-空穴的复合几率。可见合理调控pH是制备具有高PEC性能WO₃的技术关键。

WO₃ with different crystal structures and morphologies are prepared from peroxypolytungstic acid via hydrothermal synthesis method.The effect of pH value on the crystal structure and morphology of WO₃ are investigated.The results show that the controllable synthesis of crystal and morphology of WO₃ can be achieved by adjusting pH value;the crystal structure has an important influence on the visible light absorption capacity of WO₃;different crystal phases of WO₃ lead to obviously different PEC performances.Cubic WO₃(c-WO₃) nanorods shows a higher PEC performance than hexagonal WO₃(h-WO₃) and hexagonal-cubic WO₃(h-c-WO₃), which may be attributed to that, (1)narrower bandgap reduces the absorption threshold of c-WO₃;(2)nanorods accelerate the transfer rate of photogenerated electrons, thus reducing the probability of electron-hole recombination.It is concluded that the reasonable regulation of pH value is the key role to prepare WO₃ with high PEC performance.

高彩云(1985-),女,博士,讲师,研究方向为太阳能高效利用,caiyunfei_520@163.com