Self‐Assembled Monolayer Stabilized Gold‐Vanadate Nanoflute for Water Splitting Reactions

Abstract

Vanadium oxide (VOx) decorated with gold‐nanoparticles via self‐assembled monolayer approach is herein reported to be an efficient electrocatalyst for both oxygen and hydrogen evolution reactions (OER and HER) in alkali medium. The voids created in the nanoflute of gold‐vanadate were believed to be responsible for high mass transfer allowing the material to be highly applicable as a catalyst for water splitting and nitro‐arene reduction. The nanoflute exhibited high current density with low onset potential value in both OER and HER. The overpotential value at 10 mAcm−2 was observed to be 310 mV with onset potential of 1.43 V in case of OER while the overpotential value for HER was measured to be 282 mV. The nanocatalyst was found to be stable upto 10 h with minimal increment in the overpotential value. The Tafel plot value of 127 mVdec−1 in OER and 131 mVdec−1 in HER also signified for the high efficacy of the catalyst towards splitting of water molecules under high basic condition. The same material was also used as catalyst for reduction of various nitro‐arenes in isopropanol with 0.25 M KOH. The liberation of hydrogen via the oxidation of isopropanol was supposed to be responsible for reduction of nitro‐arenes. The ability of the catalyst to oxidize isopropanol was substantiated from electrochemical studies.

Direct cyanidation of silver sulfide by heterolytic C–CN bond cleavage of acetonitrile

“…25,26 Usually, the binding energy values of sulfur (S) in suldes are observed in the range of 162-164 eV. 27,28 It is pertinent to mention that the oxidation of S 2À to S x O y did not happen in the absence of V 2 O 5 . This clearly suggests that the Scheme 1 Synthesis of AgCN by cyanidation of Ag 2 S. a The values in the parentheses represent the amounts in mmol.…”

Nanoporous Gold‐Based Materials for Electrochemical Energy Storage and Conversion

“…Hydrogen (H 2 ) provides the highest gravimetric energy density among all chemical fuels (142 MJ kg −1 , upper heating value), and can be considered the ultimate clean energy resource due to zero emission of carbonaceous species, [1f] and is suitable as a fuel for proton‐exchange membrane fuel cells for high‐energy devices. [ 4 ]…”

“…Among the several possible carbon‐free electricity sources, those based on electrochemical and photochemical water‐splitting processes are the most promising ones [ 1,3 ] and environmentally benign, [ 4 ] especially when coupled with fuel cells and internal combustion engines for recovery of the chemical energy stored as H 2 and O 2 ( Figure 2 A). In this process , solar energy and/or electricity are used to simultaneously promote the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER), according to the respective semireactions.…”

“…[1,2] In fact, according to the International Energy Agency, renewable power capacity is expected to expand by 50% from 2019 to 2024, led by solar energy-based sources. [2] Among the several possible carbon-free electricity sources, those based on electrochemical and photochemical watersplitting processes are the most promising ones [1,3] and environmentally benign, [4] especially when coupled with fuel cells and internal combustion engines for recovery of the chemical energy stored as H 2 and O 2 (Figure 2A). In this process À…”

“…Hydrogen (H 2 ) provides the highest gravimetric energy density among all chemical fuels (142 MJ kg À1 , upper heating value), and can be considered the ultimate clean energy resource due to zero emission of carbonaceous species, [1f] and is suitable as a fuel for protonexchange membrane fuel cells for high-energy devices. [4] Because hydrogen gas is a clean fuel with high energy content and dioxygen is the most widely used oxidizing agent in fuel cells, the energy stored in their chemical bonds can be conveniently converted to electricity while recovering water, the starting material, [1g] through an ideal environmentally benign cyclic process. The oxygen reduction reaction (ORR) is the cathodic semireaction and plays a fundamental role in fuel cell operation.…”