Beyond Graphene: A Review of Graphene's Lesser-Known Yne Relatives and their Energy Applications

Abstract

Exploration of two-dimensional (2D) carbon materials has been intensified due to their exceptional properties and transformative potential across energy and electronic domains. Among the lesser-known graphene relatives, graphyne (GY), graphdiyne (GDY), graphtriyne (GTY), and graphtetrayne (GT4Y) are uniquely integrated with sp- and sp²-hybridized carbon atoms, resulting in tunable band gaps, high surface area, enhanced porosity, and superior carrier mobility. Characterized by remarkable thermal conductivity, mechanical strength, and chemical stability, these materials hold immense promise in energy storage, electronics, optoelectronics, sensing, biomedical, and membrane technologies. Ongoing research addresses challenges in scalable synthesis, defect regulation, and material integration, enabling innovative applications in renewable energy, biotechnology, and advanced materials. This article presents a comprehensive comparative investigation of synthesis strategies, structural modifications, and electronic and mechanical properties, with a focus on their performance in photovoltaics, thermoelectrics, water splitting, batteries, and supercapacitors. Detailed properties include GDY’s extended conjugation and charge transport, GTY’s mechanical flexibility, and GT4Y’s enhanced thermal stability. By consolidating recent advancements and identifying critical gaps, this review establishes a foundational framework for the rational design and future deployment of yne-functionalized 2D carbon materials in interdisciplinary energy and electronic applications.