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

Environ Res. 2021 Jun:197:111134. doi: 10.1016/j.envres.2021.111134. Epub 2021 Apr 6.


The realization of artificial photosynthesis in the photocatalytic CO2 transformation into valuable chemicals or solar fuels, such as CO, CH4, HCOOH, and CH3OH, 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 CO2 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 (S-scheme) 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 CO2 conversion.

Keywords: Doping; Hetero-structuralization; Oxygen vacancies; Photocatalytic CO(2) reduction; Zinc oxide (ZnO).

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Carbon Dioxide
  • Catalysis
  • Light
  • Oxides
  • Zinc Oxide*


  • Oxides
  • Carbon Dioxide
  • Zinc Oxide