Revisiting photo and electro-catalytic modalities for sustainable conversion of CO2

[Display omitted] •Excessive release of CO2 in environment causes global warming.•Efficient reduction of CO2 into various value added-products via photo- and electro catalytic reduction reactions.•Homogenous and heterogeneous catalytic systems for CO2 reduction are discussed.•Recent advances in single atom catalysis for carbon dioxide reduction are reviewed. There is a dire need for sustainable and renewable energy sources. Carbon dioxide (CO2) transformation by photochemical and electrochemical reduction reactions (CO2RR) is promising for producing valuable products. Both these technologies have demonstrated incredible potential to produce zero-carbon-emission fuels. Hence, reducing CO2 needs catalysts as a climacteric tool regardless of its reaction-modes, such as photocatalytic, photoelectrocatalytic, and electrocatalytic. In this review, the fundamentals, concepts, mechanisms, related photo and electrocatalysts, role of photosensitizers, interaction of CO2 with surfaces of electrodes, enzyme assisted photocatalytic reduction, and recent developments in single-atom catalysis for CO2 reduction along with future perspectives have been documented in details.