Photocatalysis based on the use of semiconducting materials is an emerging alternative to conventional thermochemical catalysis, and it has the potential to promote chemical synthesis under greener and milder conditions. However, heterogeneous photocatalytic organic reactions are still in their infancy, limited by the low-efficiency carrier separation of the currently available photocatalytic materials. Here, we report photochromic Bi₂WO_6–x/amorphous BiOCl (p-BWO) nanosheets, which, distinct from pristine Bi₂WO₆, show blue colouration upon visible light irradiation and are bleached by atmospheric oxygen. Studies on the microscopic structure of the material reveal the existence of abundant W_(vi)O_6–x units, which serve as the sites for the fast and continuous consumption of photogenerated electrons, thereby effectively facilitating the separation of electron–hole pairs. The prepared composite features a remarkable enhancement in performance for the photocatalytic oxidation of toluene with a conversion rate 166-fold higher compared with that of pristine Bi₂WO₆.

基于半导体材料的光催化是传统热化学催化的新兴替代方法，它具有在更绿色和更温和的条件下促进化学合成的潜力。然而，由于目前可用的光催化材料的低效率载流子分离，非均相光催化有机反应仍处于起步阶段。在这里，我们报道了光致变色的Bi ₂ WO _{6– x} /非晶BiOCl（p -BWO）纳米片，它不同于原始的Bi ₂ WO ₆，在可见光照射下显示蓝色，并被大气氧漂白。对材料微观结构的研究表明存在大量的钨_（vi） O _{6– x}单位，它们是快速连续消耗光生电子的位置，从而有效地促进了电子-空穴对的分离。所制备的复合材料具有显着增强的甲苯光催化氧化性能，其转化率比原始Bi ₂ WO ₆高166倍。