Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University, Hong Kong, People's Republic of China.
Lab Chip. 2012 Oct 21;12(20):3983-90. doi: 10.1039/c2lc40428a.
This paper reports experimental studies using the photoelectrocatalytic effect to eliminate a fundamental limit of photocatalysis - the recombination of photo-excited electrons and holes. The fabricated reactor has a planar reaction chamber (10 × 10 × 0.1 mm(3)), formed by a blank indium tin oxide glass slide, an epoxy spacer and a BiVO(4)-coated indium tin oxide glass substrate. A blue light-emitting diode panel (emission area 10 × 10 mm(2)) is mounted on the cover for uniform illumination of the reaction chamber. In the experiment, positive and negative bias potentials were applied across the reaction chamber to suppress the electron/hole recombination and to select either the hole-driven or electron-driven oxidation pathway. The negative bias always exhibits higher performance. It is observed that under -1.8 V the degradation rate is independent of the residence time, showing that the accompanying electrolysis can solve the oxygen deficiency problem. The synergistic effect of photocatalysis and electrocatalysis is observed to reach its maximum under the bias potential of ± 1.5 V. The photoelectrocatalytic microreactor shows high stability and may be scaled up for high-performance water purification.
本文报道了利用光电催化效应消除光催化基本限制的实验研究 - 光激发电子和空穴的复合。所制备的反应器具有平面反应室（10×10×0.1mm（3）），由空白氧化铟锡玻璃片、环氧树脂间隔物和涂覆氧化铟锡玻璃基底的 BiVO（4）组成。在盖上安装了一个蓝色发光二极管面板（发射面积为 10×10mm（2）），用于均匀照射反应室。在实验中，在反应室上施加正负极偏压以抑制电子/空穴复合，并选择空穴驱动或电子驱动的氧化途径。负偏压始终表现出更高的性能。观察到在-1.8V 下，降解速率与停留时间无关，表明伴随的电解可以解决缺氧问题。观察到光催化和电催化的协同效应在±1.5V 的偏压下达到最大值。光电催化微反应器表现出高稳定性，并且可以进行放大以实现高性能水净化。
