LDHs材料的制备及光催化应用研究进展

Research Progress on Synthesis of Layered Double Hydroxides(LDHs) and Their Applications in Photocatalysis

层状双金属氢氧化物(layered double hydroxides,LDHs)具有层板化学组分可调、层间阴离子易交换、插层分子种类多、比表面积大等优点,可作为理想的光催化剂,具有重要的应用前景。LDHs光催化剂的制备方法主要有共沉淀法、水热法、离子交换法等,在此基础上,探讨了LDHs光催化材料在光催化产氢或产氧、光催化还原CO_2、光降解有机污染物以及光电催化等领域的应用。尽管LDHs材料的光催化应用研究取得了良好的进展,但是LDHs光催化材料的催化活性仍然较低,实现太阳能的高效利用及光催化反应过程的高转化率仍然具有很大的挑战性。针对这一困境,可以采取以下措施:①开发新的纳米材料合成技术,实现LDHs材料的成分、微结构的可控合成;②发展原位表征技术,直观研究光催化反应的微观动态过程和相关规律;③构建新颖的LDHs基光催化材料,使其光子吸收与利用率、光生载流子分离效率与表面催化反应效率协同提高,获得较高光催化效率。

Layered double hydroxides (LDHs) photocatalysts have emerged as one of the most ideal photocatalysts, owing to their flexibility in composition of hydroxide layer, facile exchange ability of interlayer anions and a range of intercalation molecule, and high specific surface areas.LDHs photocatalysts were prepared by coprecipitation, hydrothermal method, ion exchange route, and other techniques.As one of the promising photocatalysts, the research progress and application of LDHs photocatalysts in photocatalytic and/or photoelectrocatalytic O 2 generation and H 2 evolution, photoreduction of CO 2 , and photodegradation of organic pollutants are reviewed.Despite the many recent advances in photocatalytic performance of LDHs, the low photocatalytic efficiency of LDHs is always a key factor and great challenge to restrict the practical application of this technology.For high conversion efficiency of photocatalytic reaction, some strategies may be adoped to enhance the photocatalytic efficiencies of LDHs:① development of new synthesis methods to controllably produce LDHs with an optimum compositions and nanostructures;② exploration of advanced in-situ tehniques to directly characterize microdynamic reaction process and correlations between photocatalytic properties and influence factor for LDHs photocatalysts under reaction condition;③ design of novel LDHs-based photocatalysts to achieve high photocatalytic efficiency by the aid of synergistic enhancement in photon absorption and utilization, the separation of photogenerated carriers and surface photocatalytic reaction efficiency.