Boosting light-driven CO2 reduction into solar fuels: Mainstream avenues for engineering ZnO-based photocatalysts

Abstract

The realization of artificial photosynthesis in the photocatalytic CO 2 transformation into valuable chemicals or solar fuels, such as CO, CH 4 , HCOOH, and CH 3 OH, by solar-light harvesting is a promising solution to both global-warming and energy-supply issues. Recently, zinc oxide (ZnO) has emerged as an excellent oxidative photocatalyst among non-titanium metal oxides due to its availability, outstanding semiconducting and optical properties, non-toxicity, affordability, and ease of synthesis. However, ZnO wide bandgap and inability to absorb in the visible region has demanded particular modification for its practical use as a sustainable photocatalyst. This review provides a panorama of the latest advancement on ZnO photocatalysis for CO 2 reduction with an overview of fundamental aspects. Various modification strategies such as transition metal and non-metal doping, loading of plasmonic metals, and surface vacancy engineering for tunning the properties and improving the performance of ZnO are elaborated. Composites or hetero-structuralization-based Z-scheme formation is also presented along with a detailed photocatalytic reduction mechanism. Moreover, a new novel Step-scheme (Sscheme) heterostructure modification with a charge transfer pathway mechanism is also highlighted. Finally, the key challenges and new directions in this field are proposed to provide a new vision for further improvement for ZnO-based photocatalytic CO 2 conversion.

Single‐Atom Catalysts (SACs) for Photocatalytic CO2 Reduction with H2O: Activity, Product Selectivity, Stability, and Surface Chemistry

“…Two types of semiconducting catalysts are typically used, namely, i) wide bandgap semiconductors (e.g., TiO 2 and ZnO) and ii) narrow bandgap semiconductors (e.g., Cu 2 O and MoS 2 ). [72][73][74][75][76][77] Wide bandgap semiconductors suffer from inefficient charge separation because their wide bandgaps limit charge formation under light from the visible region of the spectrum. Many efforts have been made to improve charge transfer during catalysis.…”

Layered Double Hydroxide Engineering for the Photocatalytic Conversion of Inactive Carbon and Nitrogen Molecules

“…Sunlight-driven photocatalysis allows CO 2 and N 2 molecules to be activated and converted with water as a clean proton source under mild conditions. − Since Fujishima et al discovered that titanium dioxide has a photocatalytic effect in 1972, many photocatalytic materials have been studied and synthesized. In particular, for CO 2 and N 2 reduction reactions, various photocatalysts have been reported, such as noble-metal-loaded TiO 2 , , In 2 O 3 , , CdS, and graphitic carbon nitride (g-C 3 N 4 ). − The photothermal effect of converting near-infrared solar energy into local thermal energy has also attracted great attention in recent years to increase photocatalytic efficiency and modulate the product’s selectivity .…”

Potential of graphene based photocatalyst for antiviral activity with emphasis on COVID-19: A review

“…Recently, nanomaterials with antimicrobial features (nano-antimicrobials) exhibit an imperative role in the protection against these pathogenic viruses. In recent studies, two-dimensional (2D) materials particularly graphene-based materials, including, graphene oxide (GO), nanoporous graphene, reduced GO (r-GO) have attained great interest in desalination, water sterilization, photocatalytic disinfection, ultra-and nano-filtration, and many biomedical applications [14] , [15] , [16] , [17] , [18] . Interestingly, graphene and its derivative with antiviral characteristics display potential in the inactivation of viruses due to their high electrical conductivity and movement, specific surface area, outstanding electrochemical, piezoelectric, and mechanical characteristics [19] , [20] , [21] , [22] , [23] .…”