Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China.
Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China.
J Colloid Interface Sci. 2018 Nov 15;530:256-263. doi: 10.1016/j.jcis.2018.06.078. Epub 2018 Jun 26.
Hydrogen and oxygen produced by water splitting under solar energy are ideal future energy sources. At present, obtaining the efficient, stable and inexpensive photocatalyst for photocatalytic overall water splitting is still a huge challenge. Cobalt phosphate (CoPO, CoPi) possesses proper band positions for water splitting. However, the fast recombination of photogenerated electron and hole pairs for CoPi restricts its application. Herein, strongly coupling CoPO-carbon dots (CoPi-CDs) composite was constructed as an effective strategy to depress the fast recombination behavior of photogenerated electron and hole pairs. CoPi-CDs show superior photocatalytic water splitting activity than that of single CoPi. When the concentration of CDs in the composite is 0.002 g/g, the hydrogen production rate was obtained for approximately 0.592 μmol h, as well as the oxygen evolution rate about 0.258 μmol h (with 2:1 stoichiometry), which are both nearly 33 times than that of pristine CoPi. This enhanced photocatalytic activity of CoPi-CDs should ascribe to the efficient coupling effect between CoPi and CDs, which allows fast electron transfer at the interface of CoPi and CDs and thus effectively boosts the photocatalytic water splitting. The strongly coupling nanocomposites should be inspiring for further nanocomposite building for photocatalytic overall water splitting.
水分解产生的氢气和氧气是理想的未来能源。目前，获得高效、稳定和廉价的用于光催化全水解的光催化剂仍然是一个巨大的挑战。磷酸钴（CoPO，CoPi）具有适合水分解的能带位置。然而，CoPi 中光生电子和空穴对的快速复合限制了其应用。本文通过构建强耦合 CoPO-碳点（CoPi-CDs）复合材料作为一种有效策略来抑制光生电子和空穴对的快速复合行为。与单一组分的 CoPi 相比，CoPi-CDs 表现出优异的光催化水分解活性。当复合材料中 CDs 的浓度为 0.002 g/g 时，其产氢速率约为 0.592 μmol h，产氧速率约为 0.258 μmol h（2:1 化学计量比），分别是纯 CoPi 的近 33 倍。CoPi-CDs 增强的光催化活性归因于 CoPi 和 CDs 之间的高效耦合效应，这使得 CoPi 和 CDs 界面处的电子快速转移，从而有效地促进了光催化水分解。这种强耦合纳米复合材料为进一步构建用于光催化全水解的纳米复合材料提供了启示。
