Efficient bipolar membrane with protein interfacial layer for optimal water splitting

[Display omitted] •Layer-by-layer casting of BPM (CEL, AEL and IL) in same solvent for good adhesion.•Polarisation of water in hydrophilic protein environment under electric field.•Application of protein as interfacial layer for efficient water splitting.•Analysis of water dissociation across BPM by I–V and chronopotentiometric studies.•BPM with excellent water splitting efficiency. Herein, we are reporting bipolar membranes (BPMs) for water splitting. BPMs are sandwiched structure of anion-exchange layer (AEL) and cation-exchange layer (CEL) with a protein (lysozyme (LYS) or bovine serum albumin (BSA) as interfacial layer (IL). CEL and AEL were prepared by controlled sulphonation or chloromethylation (without chloromethyl methyl ether). Presence of acidic and basic groups in the IL facilitates the H+/OH− transport and act as proton/hydroxide buffer. Further, water dissociation efficiency of BPMs was also analysed by experimental results (I–V curves, chronopotentiometry, and electrodialysis). Data revealed high suitability of BPM-LYS for excellent catalytic activity and water dissociation. The experimental results (I–V) curves, chronopotentiometry, and electrodialysis) revealed high suitability of BPM-LYS for excellent catalytic activity and water dissociation.