Biomimicry designs for photoelectrochemical systems: Strategies to improve light delivery efficiency

In the past years, photoelectrocatalysis has been developed to offer green and sustainable application to wastewater remediation, water disinfection, H₂ production and CO₂ reduction. The advances of these systems with new semiconductor photoelectrocatalysts that are photoexcited with visible light giving photogenerated charge carriers efficiently, separated in a photoelectrochemical cell, are explained. These studies do not consider the light transport as fundamental aspect of light–matter interaction, although the harvesting of photons at the semiconductor surface limits the quantum yield by the existing semiconductor architectures. This opinion review envisages biomimicry as an alternative natural guide for synthesizing more efficient photoelectrodes. Micro- and nanostructure shapes from nature are identified to prepare new bio-inspired photoelectrodes for photoelectrochemical reactors with the light transport as indispensable element. The implementation of strategies of phototroph organisms to maximize light adsorption and the enhancement of photoelectrocatalytic surface area are analyzed as key factors for such bio-based photoelectrodes.