Enhanced photocatalytic conversion of CO₂ over Ag-deposited TiO₂ nanotube arrays

Abstract The photocatalytic (PC) performance of the Ag-tailored TiO 2 nanotube arrays (TNTAs) for conversion of CO 2 was evaluated in this study. A facile electrochemical deposition method was employed to construct Ag-TNTAs binary nanocomposites. The size and amount of Ag nanoparticles (NPs) over TNTAs surface has been adjusted by limiting the deposition time and anodization voltage. The properties of Ag-TNTAs photocatalyst were determined using XRD, FESEM, and UV-Vis DRS. The as-fabricated Ag-TNTAs photocatalysts showed improved light response compared to pristine TNTAs. Among the Ag-modified TNTAs, Ag/TNTAs-2 exhibited the best PC CO 2 conversion rate under exposure of visible light. Increasing the deposition of Ag NPs causes the formation of the larger Ag particles and decreases electron-hole separation efficiency. The boosted PC activity of Ag-modified TNTAs can be ascribed to the synergistic effect of the surface plasmon resonance (SPR) effect of Ag NPs, which improved response of visible light and subsequently prevented the recombination of photoexcited charge carriers.