Photocatalytic CO Reduction with Dissolved Carbonates and Near-Zero CO(aq) by Employing Long-Range Proton Transport.

Photocatalytic CO reduction (COR) in ∼0 mM CO(aq) concentration is challenging but is relevant for capturing CO and achieving a circular carbon economy. Despite recent advances, the interplay between the CO catalytic reduction and the oxidative redox processes that are arranged on photocatalyst surfaces with nanometer-scale distances is less studied. Specifically, mechanistic investigation on interdependent processes, including CO adsorption, charge separation, long-range chemical transport (∼100 nm distance), and bicarbonate buffer speciation, involved in photocatalysis is urgently needed.

A general interfacial-energetics-tuning strategy for enhanced artificial photosynthesis.

The demands for cost-effective solar fuels have triggered extensive research in artificial photosynthesis, yet the efforts in designing high-performance particulate photocatalysts are largely impeded by inefficient charge separation. Because charge separation in a particulate photocatalyst is driven by asymmetric interfacial energetics between its reduction and oxidation sites, enhancing this process demands nanoscale tuning of interfacial energetics on the prerequisite of not impairing the kinetics and selectivity for surface reactions. In this study, we realize this target with a general strategy involving the application of a core/shell type cocatalyst that is demonstrated on various photocatalytic systems.

Biocement from the ocean: Hybrid microbial-electrochemical mineralization of CO.

Increasing concentrations of atmospheric CO are leading to rising global temperatures and extreme weather events. However, the most prominent method of removing CO via direct air capture remains cost-prohibitive. Oceans sequester carbon through several naturally occurring carbon dioxide removal (CDR) processes, one of which includes microorganisms that utilize dissolved inorganic carbon (DIC) in their metabolic processes.

A coating strategy to achieve effective local charge separation for photocatalytic coevolution.

Semiconductors of narrow bandgaps and high quantum efficiency have not been broadly utilized for photocatalytic coevolution of H and O via water splitting. One prominent issue is to develop effective protection strategies, which not only mitigate photocorrosion in an aqueous environment but also facilitate charge separation. Achieving local charge separation is especially challenging when these reductive and oxidative sites are placed only nanometers apart compared to two macroscopically separated electrodes in a photoelectrochemical cell.