Powering the World with Solar Fuels from Photoelectrochemical CO₂ Reduction: Basic Principles and Recent Advances

Abstract

Carbon neutrality has become an urgent mission for the future of mankind. Powering the world with renewable energy from solar CO2 reduction represents a promising way to accomplish this target. Photoelectrochemical (PEC) CO2 reduction, integrating the merits of photocatalysis and electrocatalysis, offers an intriguing and effective approach to realizing solar fuel production and CO2 mitigation in one shot. To stimulate research efforts in PEC CO2 reduction, a comprehensive review of recent advances in this field is presented, with a special emphasis on the general design motives for the assembly of highly efficient PEC cells. First, basic principles and evaluating parameters of PEC CO2 reduction cells are introduced. Then, recent innovative PEC cells with highly active photocathodes for CO2 reduction to different target chemicals are highlighted and the material designing principles are discussed. In addition, the representative self‐biased PEC CO2 reduction cells including the tandem and artificial‐leaf configurations are also addressed. Finally, this review is concluded with remarks on the present achievements in PEC CO2 reduction to different chemicals, pointing out some effective strategies to promote the efficiencies for solar fuel production. A vision of the challenges and opportunities for how to forward PEC CO2 reduction research is further provided.

Aqueous Photoelectrochemical CO2Reduction to CO and Methanol over a Silicon Photocathode Functionalized with a Cobalt Phthalocyanine Molecular Catalyst

“…[2] Photoelectrocatalytic (PEC) CO 2 reduction further lowers the energy input by harvesting solar energy in tandem with an applied voltage. [3] Major challenges of the CO 2 reduction reaction are its slow kinetics, low selectivity owing to the plurality of possible products, and competition for electrons by the hydrogen evolution reaction (HER). As the key to lowering the overpotential and achieving high activity and selectivity towards a single CO 2 reduction product, a variety of catalysts have been explored for modification of the photocathode in the PEC CO 2 reduction reaction.…”

New Insights on Catalytic Valorization of Carbon Dioxide by Conventional and Intensified Processes

“…This concept replaces the catalytic material on the surface of the photoelectrode with a natural enzyme to reduce CO 2 into the desired product. 310 Fundamentals of enzymatic conversion of CO 2 are discussed in greater details in further sections ( §5). An example of this technology is described by Moore et al 313 The authors designed a complex system for such an application, referred to as a "tandem leaf", composed of a perovskite photocathode, a BiVO 4 photoanode, a mesoporous inverse opal TiO 2 catalytic support, and the formate dehydrogenate enzyme, that was able to efficiently convert CO 2 into formate.…”

“…Photoelectrochemistry combines aspects of both photochemistry and electrochemistry. ,,,,,− By this method, electrons are generated by a photoelectrode exposed to sunlight (similarly to the photocatalytic method), but this time the photoelectrode is immersed in an electrolytic solution containing dissolved CO 2 . The photoelectrochemical valorization method is able to generate a much better charge separation and electron migration, leading to a significantly improved product output compared to the photocatalytic method .…”

One-dimensional III-nitrides: towards ultrahigh efficiency, ultrahigh stability artificial photosynthesis

“…Although these challenging requirements have limited the number of semiconductors, careful selection of semiconductors and catalyst materials, and optimization of device structures have realized the CO 2 reduction reaction. [154][155][156][157][158][159][160][161][162][163][164][165][166][167] Recently, 1D nanostructured semiconductor nanowires, nanorods, and nanobers have surpassed the CO 2 reduction reactivity of planar structures due to enhanced light absorption, shortened charge carrier pathways, and exposure of active sites. [168][169][170][171][172][173][174][175] In particular, the emerging 1D III-nitrides have shown great promise for efficient and stable conversion of CO 2 gas into target products.…”