Recent advances and challenges in graphene-based nanomaterials for photocatalytic CO2 reduction

Abstract

Photocatalytic CO₂ reduction is a viable solar-driven approach to sustainably synthesize fuels and chemicals, which provides great potential in response to the urgent threat posed by increasing atmospheric CO₂ levels. Recently, graphene-based nanomaterials have emerged as promising material due to their large surface area, superior electrical conductivity and tunable electrical properties. This study highlights the new developments in graphene-based photocatalysts for CO₂ reduction, including fundamental reaction mechanisms, thermodynamics, kinetics as well as light-induced charge separation. The presentation assesses different forms of graphenes (graphene oxide (GO), reduced graphene oxide (rGO), doped graphene and 3D graphene) with respect to their synthesis, functionality and role of functionalization, including for co-catalysts. The hybrid materials of graphene with metal oxides, semiconductors, metals, and carbon nitrides, significantly enhances charge transport and catalytic performance. The review critically evaluates the previous findings on the influence of different synthesis methods on morphology and performance and includes mechanistic information from spectroscopic and density functional theory (DFT)-based studies. In addition to advances such as single-atom catalysis, hybrid systems and machine learning-based design, the issues of catalyst stability, scalability and environmental issues are discussed. The review highlights the key pathways for developing graphene-based materials for achieving effective, scalable, and sustainable CO₂ photoreduction.