Gas involved reactions including the oxygen evolution reaction (OER), hydrogen evolution reaction (HER), oxygen reduction reaction (ORR), nitrogen reduction reaction (NRR) and carbon dioxide reduction reaction (CO₂RR) are the center of sustainable energy conversion technologies. Development of efficient catalysts to boost the aforementioned reactions is highly imperative because of the sluggish kinetics and large overpotential. Carbon-based catalysts have triggered huge interest in gas involved catalytic reactions owing to the low cost, high energy conversion efficiency and environmental friendliness. Graphdiyne (GDY), a rising-star carbon allotrope, consists of a highly π-conjugated structure of sp²- and sp-hybridized carbons. The unique electronic and topological structures and preparation advantages endow GDY with the possibilities to construct new-concept carbon-based catalysts for achieving high efficiency for energy conversion. Herein, a concise but comprehensive review of recent advances in the synthesis and applications of GDY based catalysts for crucial gas involved reactions is presented. Some new perspectives of opportunities and challenges in developing GDY-based catalysts for gas-involved energy conversion are also discussed.

The photo-conversion efficiency is a key issue in the development of new photocatalysts for solar light driven water splitting applications. In recent years, different engineering strategies have been proposed to improve the photogeneration and the lifetime of charge carriers in nanostructured photocatalysts. In particular, the rational design of heterojunctions composites to obtain peculiar physico-chemical properties has achieved more efficient charge carriers formation and separation in comparison to their individual component materials. In this review, the recent progress of sulfide-based heterojunctions and novel nanostructures such as core-shell structure, periodical structure, and hollow cylinders is summarized. Some new perspectives of opportunities and challenges in fabricating high-performance photocatalysts are also discussed.