Open Access

ARTICLE

Photothermal Methane-to-Ethanol Conversion over Cu Single-Atom–Cu₉S₅ Coupled Crystalline Carbon Nitride

Xiaohan Zhang¹, Han Song^2,*, Maoyuan Yin³, Xiaoli Rong²

1 Basic Education Department, Heze Vocational College, Heze, 274000, China
2 Department of Food Science and Chemical Engineering, Heze Vocational College, Heze, 274000, China
3 Research and Technology Service Center, Heze Vocational College, Heze, 274000, China

* Corresponding Author: Han Song. Email:

Chalcogenide Letters 2026, 23(1), 5 https://doi.org/10.32604/cl.2026.076594

Received 11 October 2025; Accepted 23 November 2025; Issue published 26 January 2026

Abstract

We report the rational design and synthesis of a novel trifunctional catalyst comprising atomically dispersed copper single-atom (Cu-SAC) sites and Cu₉S₅ nanoparticles co-loaded onto a highly crystalline carbon nitride (CCN) support for the photothermal conversion of methane to ethanol. The distinct active sites operate in synergy: the Cu-SAC sites, coordinated to the nitrogen-rich CCN framework, serve as highly efficient centers for the initial activation of methane’s C-H bond to form methyl radicals, while the plasmonic Cu₉S₅ nanoparticles act as dedicated sites for the subsequent C-C coupling and partial oxidation steps, driven by a combination of photochemical and photothermal effects. Under mild conditions (200°C, full-spectrum light), the optimized Cu-SAC–Cu₉S₅/CCN catalyst achieves an exceptional ethanol production rate of 385 μmol g⁻¹ h⁻¹ with a selectivity of 85% at a methane conversion of 5.2%. Mechanistic studies reveal that a Z-scheme heterojunction between CCN and Cu₉S₅ facilitates efficient charge separation, while the spatial decoupling of C-H activation and C-C coupling functions is crucial for suppressing the formation of CO₂. This work presents a powerful catalyst design strategy that integrates atomically precise active sites with plasmonic co-catalysts for tackling challenging chemical transformations.

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Keywords

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