College of Science, Central South University of Forestry and Technology, Changsha 410004, China.
Joint International Research Laboratory of Biomass Energy and Materials, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China.
J Hazard Mater. 2023 Mar 15;446:130689. doi: 10.1016/j.jhazmat.2022.130689. Epub 2022 Dec 27.
Hydrogel, a common carrier of photocatalyst that suffers from compromised catalytic efficiency, is still far from practical application. Herein, based on "computer chip-inspired design", a novel nanocellulose/carbon dots hydrogel (NCH) was fabricated as superior intensifier instead of common carrier of sodium titanate nanofibre (STN), where carbon dots (CDs) enhanced amino group-induced adsorption for Cr(VI), promoted photocatalytic properties of STN via transferring the photogenerated electron-hole pairs and improved amino group-induced desorption for reduced product (Cr(III)) via electrostatic repulsion, showing an efficiency of 1 + 1 > 2. Adsorption and photocatalysis experiments demonstrated superior removal performance of the NCH incorporating STN, as shown by theoretical maximum adsorption capacity of 425.74 mg/g and kinetic constant of 0.0374 min in the photocatalytic process, which was nearly 6.6 and 7.3 times of STN. A series of experiments was conducted to confirm the novel mechanism of CDs-enhanced adsorption-photocatalysis-desorption synergy. This work not only provides new insights into the fabrication of a superior intensifier for nanosized photocatalyst, but also proposes one new mechanism of CDs-enhanced adsorption-photocatalysis-desorption synergy, which is helpful for designing and optimizing nanosized photocatalyst.
水凝胶作为光催化剂的常见载体，其催化效率受到影响，仍远未达到实际应用的程度。在此，基于“计算机芯片启发式设计”，我们制备了一种新型纳米纤维素/碳点水凝胶（NCH）作为增强剂，而不是将钛酸钠纳米纤维（STN）作为普通载体，其中碳点（CDs）通过增强氨基诱导的吸附作用来增强 Cr(VI)的去除效果，通过转移光生电子-空穴对来促进 STN 的光催化性能，并通过静电排斥作用来增强氨基诱导的还原产物（Cr(III)）的解吸作用，从而表现出 1+1＞2 的协同效果。吸附和光催化实验表明，结合了 STN 的 NCH 具有优异的去除性能，其在光催化过程中的理论最大吸附容量为 425.74 mg/g，动力学常数为 0.0374 min，分别是 STN 的 6.6 倍和 7.3 倍。进行了一系列实验来证实 CD 增强吸附-光催化-解吸协同作用的新机制。这项工作不仅为纳米光催化剂的优质增强剂的制备提供了新的思路，还提出了一种新的 CD 增强吸附-光催化-解吸协同作用机制，有助于纳米光催化剂的设计和优化。
