Photocatalytic reduction of CO₂over Ag/TiO₂nanocomposites prepared with a simple and rapid silver mirror method

Abstract

The photocatalytic reduction of CO2 over Ag/TiO2 composites prepared with a simple silver mirror reaction method was investigated under UV-visible irradiation in both gas-phase (CO2 + water vapor) and aqueous solution (CO2-saturated NaHCO3 solution) systems. The as-prepared Ag/TiO2 nanocomposite exhibits efficient photocatalytic activity due to the surface plasmonic resonance and electron sink effect of the Ag component, which was found to be closely related to the size and loading amount of Ag. The rapid silver method is effective at curbing the size of Ag, so photocatalytic activity can be improved. Diverse organic chemical products were detected, including mainly methane and methanol as well as a small amount of C2 and C3 species such as acetaldehyde and acetone. Possible photocatalytic mechanisms were proposed. This artificial photosynthesis process may give a prosperous route to the removal of CO2 while simultaneously converting CO2 to valuable fuels based on highly efficient photocatalysts.

Photocatalytic reduction of CO 2 with H 2 O over graphene oxide-supported oxygen-rich TiO 2 hybrid photocatalyst under visible light irradiation: Process and kinetic studies

“…Therefore, the ability to harness the power of CO 2 on a large scale and integrate it back into the utilization cycle as a sustainable form of energy production is highly desirable. Among the various renewable projects to date, the photocatalytic reduction of CO 2 into energy-bearing products has garnered interdisciplinary research attention to mitigate the evergrowing CO 2 concentration and to meet the long-term worldwide energy demands without utilizing further CO 2 -generating power resources [6][7][8][9][10][11][12][13][14][15]. In this context, photocatalysis, a wellorchestrated mimic of natural photosynthesis, for direct conversion of solar energy to chemical energy, presents an opportunity to kill these two birds with one stone [16][17][18][19].…”

Ni‐Nanocluster Modified Black TiO2 with Dual Active Sites for Selective Photocatalytic CO2 Reduction

“…The most extensively adopted procedures are metal or nonmetal doping to improve optical property by replacing Ti 4+ and O 2− ions in the TiO 2 lattice. This doping effect and additional surface plasmon resonance from noble metal highly influence the photocatalytic performance of TiO 2 . In the metal‐doped TiO 2 photocatalyst system, Ni‐doped TiO 2 has been demonstrated to enhance the photocatalytic activity for water splitting and photodegradation due to the improved light harvesting and charge carrier lifetime.…”

Graphdiyne: A New Photocatalytic CO2 Reduction Cocatalyst

“…First-principle calculation and in situ X-ray photoelectron spectroscopy measurement reveal that the delocalized electrons in GDY can hybrid with the empty orbitals in TiO 2 within the TiO 2 /GDY network, leading to the formation of an internal electric field at the interfaces, pointing from GDY to TiO 2 . [23][24][25][26][27][28] However, noble metals are scarce and expensive, hindering their prospect severely. These effects, in combination with the photothermal effect of GDY, result in enhanced charge separation and directed electron transfer, enhanced CO 2 adsorption and activation as well as accelerated catalytic reactions over the TiO 2 /GDY heterostructure, thereby resulting in significantly improved CO 2 photoreduction efficiency and meanwhile with remarkable selectivity.…”

“…[12][13][14][15][16] However, the photocatalytic efficiency of unitary TiO 2 is still far away from the practical requirements largely due to its rapid electron-hole recombination. [23][24][25][26][27][28] However, noble metals are scarce and expensive, hindering their prospect severely. [21,22] Up to now, various cocatalysts have been exploited to promote the photocatalytic performance of TiO 2 and the most widely used cocatalysts were noble metals, such as Pt, Pd, Au, Ag, and their alloys.…”