Exploring the hydrogen evolution capabilities of earth-abundant ternary metal borides for neutral and alkaline water-splitting

Amorphous ternary metal borides in the form of Co-M-B (where, M = Fe, Ni, Cu, Mo, Mn, W or Cr) were developed for electrocatalytic hydrogen evolution in neutral and alkaline solutions. Except for Co-Cr-B, all the Co-M-B catalysts showed better hydrogen evolution rate than Co-B, with the lowest overpotential of 95 mV and 67 mV (at 10 mA/cm2) recorded for optimized Co-Mo-B catalyst, in pH 7 and pH 14, respectively. The reasons for enhancement in electrocatalytic rate, with inclusion of a second metal in Co-B, were investigated by considering several material related factors, such as, physical and electrochemical surface area, turn-over frequency, surface elemental states & composition and charge-transfer resistance. These experimental results were complemented with computational investigations to identify the most suitable sites for hydrogen adsorption and determine their H-adsorption energies. In the end, industrial feasibility of the developed Co-M-B catalysts was illustrated by performing stability and recycling tests

Evaluation of photocatalytic activity of commercial red phosphorus towards the disinfection of E. coli and reduction of Cr (VI) under direct sunlight

Elemental photocatalysts are getting the attention of material scientists as a new class of visible light photocatalysts in recent years. Hence it is important to understand and evaluate their phtocatalytic activity for the rationale design and development of new catalysts at low cost. In this regard, we choose commercial red phosphorus as elemental photocatalyst and we evaluate its activity towards the disinfection of E. coli and reduction of Cr (VI) under natural sunlight. The measured bandgap of red phosphorus is 2.0 eV matches with theoretical value and indicates the suitability of the material as photocatalyst under direct sunlight. Moreover, red phosphorus also has optimum valence and conduction band levels for the successful photo-generation of reactive oxygen species (ROS). These photogenerated ROS could help to achieve the disinfection of E. coli in 50 min. In the case of photocatalytic reduction of Cr (VI), 98% of Cr (VI) reduction has been achieved is in 60 min at pH 2. The rate of Cr (VI) reduction decreases with an increase in pH value similar to the reports with other metal oxide photocatalysts