The mechanism of HER in an alkaline solution involves an additional step of breaking water molecules to generate protons. This process, therefore, requires extra energy for successful water splitting and causes more sluggish reaction kinetics. This is depicted by the Tafel value for the optimized CoxB-[0.2]P-O which was observed to be the lowest among the investigated sample series at 49 mV dec -1 , which is competitive to Pt/C (35 mV dec -1 ) (Fig. C). Such a low value infers an enhanced electron-coupled water dissociation step, known to be the rate-determining step for HER in alkaline conditions. This demonstrates that our boron This comparison proves a better adsorption-desorption efficiency of the reactants due to better charge transfer by the reduced binding energy due to the P co-doping. The control catalyst Co(OH)2 exhibits the highest Rct value most likely since this material did not include cobaltboride or phosphite in the structure. The electronic configuration of cobalt determined by XPS analysis showed that the presence of both B and P of phosphite ensured the tailored chemistry of Co through charge transfer processes, and as a consequence the observed better charge transfer in CoxB-[0.2]P-O. Among the series of catalysts, only the Co(OH)2 control catalyst exhibits a purely crystalline form (Fig. and Fig. ), whereas both, CoxB-[0.2]P-O and CoxB-O, show mixed amorphous-crystalline heterostructures. We therefore conclude that the chemistry (boron and phosphite incorporation) as well as the co-existence of mixed phases cause the synergistic enhancement of the electron transfer process.