Graphitic-C3N4/TiO2(B) S-scheme Heterojunctions for Efficient Photocatalytic H2 Production and Organic Pollution Degradation

TL;DR

This study develops an S-scheme g-C3N4/TiO2(B) heterojunction photocatalyst that enhances solar-driven hydrogen production and organic pollutant degradation through improved light absorption and charge separation.

Contribution

It introduces a novel g-C3N4/TiO2(B) heterojunction with extended light absorption and efficient charge separation, demonstrating superior photocatalytic performance.

Findings

H2 evolution rate of 1.98 mmol g-1 h-1 under simulated sunlight

Degrades 98.2% of amoxicillin wastewater in 90 minutes

Shows excellent activity for degrading various organic antibiotics and dyes

Abstract

Achieving both broad solar-spectrum absorption and strong redox capability is critical for semiconductor photocatalysts in environmental remediation and energy conversion. Herein, an S-scheme heterojunction photocatalyst is constructed by coupling TiO2(B) nanorods with g-C3N4 nanosheets. Its well-matched band structure extends light absorption from the UV to the visible region and enables efficient charge separation. Under simulated sunlight irradiation, the 40 wt% g-C3N4/TiO2(B) heterojunction delivers a H2 evolution rate of 1.98 mmol g-1 h-1 for water reduction with methanol as the sacrificial agent, which is 1.5 and 2.0 times higher than those of pure g-C3N4 and TiO2(B), respectively. When exposed to amoxicillin wastewater instead of methanol solution, the heterojunction degrades 98.2% of amoxicillin and produces 20.70 umol g-1 of H2 within 90 min. Moreover, the heterojunction shows excellent photodegradation activity toward various organic antibiotics and dyes, owing to the S-scheme charge separation mechanism. This work highlights the promising potential of S-scheme heterojunctions for photocatalytic H2 production coupled with organic wastewater treatment.