Reflections on Photocatalysis Progress Since the Inspiration of Prof. David Ollis in 1992

Abstract

Why has photocatalysis not gained the wide-ranging commercial applications in environmental purification of air and water that seemed promising 30+ years ago since the first international conference on TiO₂ photocatalytic purification and treatment of water in 1992? The primary reason lies in its low intrinsic efficiency. The progress of R&D to enhance this efficiency has been slow, possibly due to an incomplete understanding of the underlying mechanisms of photocatalysis. There is also the possibility that certain factors, with effects comparable to those of the band gap, significantly influence photocatalytic performance but remain underexplored. Additionally, challenges such as mass transfer limitations and surface contamination hinder the industrial application of photocatalysts. It may be time for scientists to reconsider and address the limitations and practical application scenarios of photocatalysis.

Keywords

Photocatalyst / TiO₂ / Mechanisms / Water treatment / Air purification / Electron-hole recombination

Author Contributions

Conceptualization, W.A.A.; Investigation, W.A.A., L.Z., M.M., Z.Z.; Writing—Original Draft Preparation, L.Z.; Writing—Review & Editing, W.A.A., M.M., Z.Z.; Visualization, L.Z.; Supervision, W.A.A.

Ethics Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Funding

This research received no external funding.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

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