光生载流子在半导体/溶液界面处发生的表面复合过程，是制约半导体光电极体系光-电转化效率提高的关键因素之一. 本文利用光电流测量和交流阻抗等技术，初步研究了Na₂CO₃对TiO₂纳米管电极表面光电化学水分解反应的催化作用，并对“TiO₂/溶液”界面处与阳极析氧有关的光生电荷传输过程及特点进行了探讨. 结果表明，在0.5 mol•L^-1 NaClO₄溶液中加入少量的Na₂CO₃（1 mmol•L^-1），能够显著促进光生空穴穿过TiO₂/溶液界面向溶液中的传输，有效地抑制光生载流子的表面复合过程，从而相应地增大外电路的光电流，提高TiO₂光电极体系的光-电转化效率.

Surface recombination of the photogenerated electron-hole pairs at semiconductor/electrolyte interface is one of the most essential reasons responsible for lowering photoconversion efficiency (Φ) of light to chemical energy for photoelectrochemical (PEC) water splitting reaction. In this paper，the catalytic effect of sodium carbonate on the oxygen evolution reaction (OER) over TiO₂ nanotubes photoanode during PEC water splitting was investigated by performing photocurrent and ac impedance measurements. It was demonstrated that the addiction of 1 mmol•L^-1 Na₂CO₃ in 0.5 mol•L^-1 NaClO₄ electrolyte can effectively improve the charge transfer properties for the photogenerated holes across TiO2/electrolyte interface and inhibit the recombination of photogenerated carriers at this interface. As a result，both the measured photocurrent was increased and the photoconversion efficiency was enhanced.