Toward High-Efficiency Photovoltaics-Assisted Electrochemical and
Photoelectrochemical CO2 Reduction: Strategy and Challenge
Abstract
The realization of a complete techno-economy through a significant
carbon dioxide (CO2) reduction in the atmosphere has been explored in
various ways. CO2 reduction reactions (CO2RRs) can be induced using
sustainable energy, including electric and solar energy, using systems
such as electrochemical (EC) CO2RR and photoelectrochemical (PEC)
systems. This study summarizes various fabrication strategies for
non-noble metal, copper-based, and metal-organic framework-based
catalysts with excellent FE for target carbon compounds, and for noble
metals with low overvoltages. Even though EC and PEC systems exhibit
high energy-conversion efficiency using excellent catalysts, they are
not completely bias-free operations because they require external power.
Therefore, photovoltaics, which can overcome the limitations of these
systems, have been introduced. The utilization of silicon and perovskite
solar cells for photovaltaics-assisted EC (PV-EC) and
photovaltaics-assisted PEC (PV-PEC) CO2RR systems are cost efficient,
and the III-V semiconductor photoabsorbers achieved high solar-to-carbon
efficiency. This review focuses on all the members composed of PV-EC and
PV-PEC CO2RR systems and then summarizes the special cell
configurations, including the tandem and stacked structures. Moreover,
current problems such as a low energy conversion rate, expensive PV,
theoretical limitations, and scale-up to industrialization are discussed
with the suggested direction.