Effect of Excess B in Ni₂P-Coated Boron Nitride on the Photocatalytic Hydrogen Evolution from Water Splitting

Abstract

The use of hexagonal boron nitride (hBN) to modify a semiconductor photocatalyst is one of the promising methods for the production of hydrogen from water splitting. This is due to the unique characteristics of the hBN-suppressing recombination of the photogenerated charge carriers and hence increase in the redox reactions. In the present work, a hBN-modified Ni2P-containing excess boron composite (B-hBN-Ni2P) was prepared through an electroless plating method. The solid structure, elemental composition, and morphology were investigated via X-ray diffraction, energy-dispersive X-ray spectroscopy, scanning electron microscopy, UV–visible spectroscopy, and photoluminescence spectroscopy. The composite coating was tested for solar water splitting, and a hydrogen evolution rate of 883 μmol/h was achieved. The role of excess B was revealed through an electrochemical acidic leaching. By gradually removing boron from the structure, a monotonous drop in the water splitting activity was observed. Our study identifies B as a sacrificial agent/hydrogen production booster. It contributes to the higher catalytic activity with an additional hydrogen generation through the oxidation of its surplus amount from the composite coating. The enhanced hydrogen evolution activity for the composite coating in the present study is highly competitive with the other modern photocatalysts.

Development of Sustainable Catalyst Coating of Ni2P Engineered SrTiO3 Nanocubes for Hydrogen Generation

“…This is achieved by thinking of constructing a catalyst material in the form of a stable coating. Inspired from the catalytic activity boosting of Ni 2 P with semiconductors from literature supports and from our previous studies, ,− we planned to develop a SrTiO 3 engineered Ni 2 P photocatalyst with successful compositional tuning. However, the imperative feature in this engineering process is that it is in the form of a coating where Ni 2 P as a catalyst bed provides the space for SrTiO 3 decoration.…”

“…The data obtained with the test samples as per our study is compared with ultrapure hydrogen gas purchased commercially. The apparent quantum efficiency (AQE) for hydrogen generation from water splitting is calculated based on eq , , AQE = ( 2nH 2 N A h c / I λ S t ) × 100 where nH 2 is the number of moles of evolved hydrogen, N A is Avogadro’s number (6.023 × 10 23 mol –1 ), h is Planck’s constant (6.626 × 10 –34 J s), c is the velocity of light (3 × 10 8 m s –1 ), I is the experimental light intensity (76.43 mW cm –2 ), λ is the wavelength of absorbed light (in nm), S is the area of light beam exposed (in cm 2 ), and t is the irradiation time (in seconds). The band gap E g for this engineering process is determined with the Tauc relation given in eq , α italich ν = false( italicA italich ν − italicE normalg false) italicn where A is a constant, E g is the band gap, and n is a number equal to 1/2 for the direct band gap.…”

“…The data obtained with the test samples as per our study is compared with ultrapure hydrogen gas purchased commercially. The apparent quantum efficiency (AQE) for hydrogen generation from water splitting is calculated based on eq 1, 29,30…”

“…The bath composition corresponding to the preparation of Ni 2 P is selected, and its photocatalytic performance evaluation is made as per the authors' previous work. 29 This is followed by the compositional tuning in the coating by varying the loading amount of SrTiO 3 in the bath, and the photocatalytic hydrogen generation mechanism on the surface of the as-tuned SrTiO 3 − Ni 2 P coating is studied in detail. The application of the developed photocatalyst in the form of a coating rather than powder leads to an easy recovery from the test media with retained stability and activity.…”

Re Modulation of Metallic Ultrathin 2M-WS2 for Highly Efficient Hydrogen Evolution in Both Acidic and Alkaline Media

“…With the increasingly serious problems of environmental pollution and energy shortage, it is very important to develop green and efficient renewable energy. − In order to seek sustainable and renewable energy, unremitting efforts have been made to develop practical energy conversion technologies. Hydrogen is considered as a clean and pollution-free energy with a high energy density (120 MJ kg –1 ), and hydrogen evolution reaction (HER) is a promising carbon-free hydrogen production option among various advanced technologies. − Noble metal (Pt, Ir, and Ru)-based electrocatalysts and rare metallic oxides exhibited excellent HER performance. − However, the scarcity and high price limit their large-scale application. − Therefore, tremendous efforts have been contributed to searching for the non-noble metal electrocatalysts with aplenty and stable reserves, such as transition metal dichalcogenides (TMDs). − In addition, to meet different application demands, development of electrocatalysts with excellent stability and high activity in varied pH has been actively pursued. − …”