Interfacial photothermal evaporation coupled with photocatalytic water splitting for hydrogen production

In recent years, photocatalytic technology has emerged as a promising approach for converting solar energy into storable hydrogen fuel, demonstrating significant application potential in the fields of environmental remediation and energy conversion. Current research in photocatalysis predominantly focuses on material design, while largely overlooking the optimization of photocatalytic reaction systems. In response to this, a new study published in Green Chemical Engineering reports a novel immobilized photothermal-photocatalytic integrated system developed by a research team led by Professor Maochang Liu from Xi'an Jiaotong University.

“Specifically, conventional photocatalytic water splitting typically involves uniformly dispersing photocatalysts in the liquid phase, forming a solid-liquid-gas triphase reaction system,” shares Sun. “This triphase system inherently suffers from low solar energy utilization efficiency and slow mass transfer processes.”

Typically, conventional photocatalytic reactions primarily rely on ultraviolet and visible light spectra, failing to effectively utilize near-infrared light, which constitutes over 50% of the solar spectrum. “The development of novel reaction systems with full-spectrum responsiveness has emerged as a critical breakthrough for enhancing photocatalytic efficiency,” says Liu.

In this study, the researchers have successfully developed an immobilized photothermal-photocatalytic integrated system. This innovative system combines a photothermal substrate with high-performance photocatalysts, enabling a synergistic process of liquid water evaporation and steam-phase water splitting for hydrogen production under light illumination without requiring additional energy input. Regarding photocatalyst design, a CdS/CoFe₂O₄ (CCF) p-n heterojunction photocatalyst is fabricated by the calcination method, which facilitates consistent spatial transmission and efficient separation of photogenerated carriers. System construction involves utilizing annealed melamine sponge (AMS) as a photothermal substrate, transforming the solid-liquid-gas triphase system into a more efficient gas-solid biphase configuration. The optimized CCF/AMS gas-solid biphase system demonstrates a remarkable hydrogen evolution rate of 254.1 µmol h^–1, representing a significant leap forward compared to traditional triphase system.

“This gas-solid biphase system can enhance solar energy utilization efficiency, elevate the overall reaction temperature, and reduce gas transport resistance at the catalytic interface, thereby significantly improving the efficiency of photocatalytic water splitting.” explains Liu.

This study, through innovative material design and reaction system construction, provides crucial insights and practical guidance for enhancing the efficiency of photocatalytic water splitting.

About GreenChE
GreenChE focuses on the significant cutting-edge research and the latest technological advances in core areas of green and sustainable development of chemistry and chemical engineering as well as in other relevant disciplines.
In addition, GreenChE is indexed in prominent databases such as ESCI, EI, DOAJ, Scopus, and CSCD, ensuring global discoverability and strong academic impact.