Low-Cost Microalgae-Templated CdS Composite for CO2 Utilization: Dye Sensitization of Phycobiliproteins and Carbon Dioxide Reduction

This study developed a bio-semiconductor composite photocatalytic system (Gs/CdS) based on the microalgae Galdieria sulphuraria (Gs) template, aiming at the major bottlenecks faced by traditional semiconductor materials (such as CdS) in CO₂ reduction: the susceptibility to photocorrosion, high carrier recombination rate. By taking advantage of the synergistic effect between the natural active substances of microalgae and semiconductors, a new type of material with both efficient photoelectrocatalytic performance and low-cost characteristics was constructed. Experiments show that the phycobilin of Gs optimizes the charge separation efficiency through dye sensitization. The Faraday efficiency of the composite material reaches 67.20%, the methanol yield is 28.42 µmol·h⁻¹·cm⁻², and the cycling stability is excellent. Furthermore, the antenna molecules of microalgae and the photocatalytic process of CdS form a dye-sensitized effect, providing a green and sustainable strategy for the resource utilization of CO₂.

Graphical Abstract