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Interfacial Microenvironment Effects on the Mechanism of Photocatalytic Methanol Conversion for Hydrogen Evolution
Chi Lin1, Yajie Feng2, Yifei Huang2
1College of Optoelectronic Engineering, Chongqing University, Chongqing 401331, China.
The Journal of Physical Chemistry Letters
|July 2, 2026
Summary
Optimizing heterogeneous photocatalysis requires controlling the interfacial microenvironment. Methanol concentration dictates hydrogen evolution activity via a volcano-shaped curve by modulating adsorption, oxidation pathways, and proton transport.
Area of Science:
- Heterogeneous Photocatalysis
- Surface Chemistry
- Materials Science
Background:
- The solid-liquid interface significantly impacts heterogeneous photocatalysis efficiency.
- Understanding the interfacial microenvironment is crucial for optimizing catalytic performance.
- The role of scavengers in modulating this interface remains underexplored.
Purpose of the Study:
- To investigate how methanol concentration regulates the interfacial microenvironment.
- To elucidate the impact of this microenvironment on hydrogen evolution activity over Cu/TiO2.
- To reveal the underlying mechanisms governing the observed catalytic behavior.
Main Methods:
- Utilized Cu/TiO2 as the photocatalyst with methanol as a model hole scavenger.
- Employed *in-situ* spectroscopy and isotopic labeling to study reaction pathways.
- Applied Raman spectroscopy and ab initio molecular dynamics for microstructural analysis.
Main Results:
- Hydrogen evolution activity exhibited a nonmonotonic, volcano-shaped dependence on methanol concentration, peaking at 60 vol %.
- Identified a switch in dominant methanol oxidation pathways based on methanol concentration.
- Disruption of the water hydrogen-bond network at high methanol content limited proton transport.
Conclusions:
- The interfacial microenvironment, regulated by methanol concentration, is key to controlling photocatalytic activity.
- Optimizing the balance between adsorption, oxidation pathways, and proton transfer is essential.
- Tailoring the interfacial microenvironment offers a strategic approach for enhancing liquid-phase heterogeneous catalysis.
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