Work

The role of activated carbon in photocatalysis

Year: 2026

Type: article

Abstract: Activated carbon (AC) has traditionally been incorporated into photocatalytic systems because of its high adsorption capacity and high specific surface area. However, growing evidence demonstrates that its role extends far beyond that of an inert support. Instead, AC acts as a multifunctional regulator of the photocatalytic microenvironment, simultaneously affecting pollutant concentration, semiconductor dispersion, interfacial charge transfer, light utilization, and surface reactivity. A bibliometric study reveals the rapid expansion of research on AC-based photocatalysts over the last decade and the progressive shift from conventional adsorption-assisted applications toward multifunctional materials for environmental and energy-related processes. Particular attention is devoted to TiO₂/AC composites, which constitute the most extensively investigated systems. Importantly, these functions are not always synergistic. Increasing AC content, for example, can enhance pollutant accumulation and facilitate charge transport while simultaneously shielding TiO₂ from incident light, indicating that photocatalytic performance is governed by a functional balance rather than by maximizing any single AC property. The review also examines the influence of surface chemistry, pore architecture, AC loading, synthesis route, and the nature of the interface therefore determine which functions dominate. Furthermore, recent strategies based on the incorporation of metal cocatalysts and semiconductor heterojunctions further expand this multifunctionality by introducing additional pathways for charge separation and redox activation. Although environmental remediation remains the dominant application, emerging studies increasingly explore hydrogen production, CO₂ conversion, and selective photocatalytic synthesis. Overall, this review proposes a shift from viewing AC as a support to considering it as a multifunctional interfacial component whose beneficial effects depend on the balance between adsorption, electronic, structural, and optical contributions. This perspective provides a framework for rationally designing AC-containing photocatalysts rather than relying primarily on high surface area or carbon loading as performance indicators.

Source: Materials Today Catalysis

DOI: 10.1016/j.mtcata.2026.100167