Fabrications Of Salicylic Acid-Modified TiO₂ Nanotube Arrays And ZnIn₂S₄ Film Electrode And Studies On Their Photoelectrocatalytic Properties

In this paper, salicylic acid (SA)-modified TiO₂ nanotube arrays and ZnIn₂S₄ film were fabricated and their visible light photocatalytic activities were investigated.This paper focused on immersion method synthesis of visible light active SA-modified TiO₂ nanotube array electrode and its photoelectrocatalytic (PEC) activity. The SA-modified TiO₂ nanotube array electrode was synthesized by immersing in SA solution with an anodized TiO₂ nanotube array electrode. Well-ordered nanotubes with open top end were formed, the average diameter was c.a. 80 nm and the average length of the nanotube was 550 ran, respectively. It was found that SA-modified TiO₂ nanotube array electrode absorbed well into visible region, the amount of surface hydroxyl groups was increased and it exhibited enhanced visible light PEC activity on the degradation of p-nitrophenol (PNP). The degradation efficiencies increased from 63 to 100% under UV light in 2 h, and 79 to 100% under visible light (λ>400 nm) in 3 h, compared with TiO₂ nanotube array electrode.ZnIn₂S₄ film was fabricated on Ti substrate by electrodeposition method. The film was composed of some subtle structures like branches and leaves. ZnIn₂S₄ film exhibited the high absorption intensity in visible light region. The crystallographic structures and photoresponse ability of the film could be affected significantly by the electrodeposition time. Among all the samples, the ZnIn₂S₄ film electrodepsiting 20 min showed the highest visible light activity and photoconversion efficiency, the highest photoconversion efficiencies were 1.35% and 2.03%, respectively.