Continuous depletion of fossil fuels insisting us to find out suitable alternative energy sources to fulfill the global energy requirement. While searching it has been found that the ‘Hydrogen’ with specific energy density value of 142 KJ/mol can plays an important role. Electrocatalytic water splitting is the only way which can generate pure hydrogen by forming water molecules as an impurity. Electrocatalytic water splitting consist of two half-cell reaction viz oxygen evolution reaction (OER) at anode and hydrogen evolution reaction (HER) at cathode. Oxide of noble metals (RuO2 and IrO2) and Pt metal are considered to be the state-of-art catalyst for OER and HER respectively. High cost and low abundance of these noble metal-based catalyst insisting us to think alternative catalyst for the practical generation large-scale hydrogen. Recently, various derivatives of transition metals are considered as an effective and low-cost alternative to the noble metal-based catalyst. Although, various transition metal based electrocatalyst have reported so far for their excellent OER and HER activity but still due low conductivity and marginal stability under static condition leads to do some strategical modification for better stability. Recently, synthesis of graphene composite with transition metal based electrocatalyst have gain a much more attention for their excellent conductivity and stability with fruitful hydrogen generation. Here in this review for very first time we have discussed recent development of various graphene-based composite of transition metal for water splitting reaction. In addition, the current contests and opportunities in this filed will be discussed elaborately with an extensive future outlook.
|Sustainable Energy and Fuels
|Accepted/In press - 2021