Mesoporous Bimetallic Au@Rh Core–Shell Nanowires as Efficient Electrocatalysts for pH-Universal Hydrogen Evolution

Abstract

Electrochemical water splitting is one hopeful strategy for hydrogen production, and designing efficient hydrogen evolution electrocatalysts under universal pH is one of the most critical topics. Here, we have successfully prepared mesoporous bimetallic core–shell nanostructures with Au nanowires (Au NWs) as cores and mesoporous Rh as shells (Au@mRh NWs). Due to the one-dimensional structure and mesoporous core–shell structure, Au@mRh NWs possess more active sites and provide the synergistic effect, leading to the great improvement of the electrochemical activity toward the hydrogen evolution reaction under a wide range of pH. The present work proposes a versatile strategy for preparing a bimetallic core–shell structure with a mesoporous shell, which is highly promising for more electrocatalytic applications.

One-pot synthesis of Au-M@SiO2 (M = Rh, Pd, Ir, Pt) core–shell nanoparticles as highly efficient catalysts for the reduction of 4-nitrophenol

“…The molar ratio of Au and Rh is 1.0 by the calculation of XPS peak areas, which is consistent with that of ICP-MS and the molar ratio of their precursors. In addition, the two peaks of Au (0) shift to the higher binding energy, which is mainly due to the electron interaction between Au and Rh 45 . The electronegativity of Au is higher than that of Rh, which results in an increased electron density of Au and a reduction of electron binding energy.…”

A phosphorus modified mesoporous AuRh film as an efficient bifunctional electrocatalyst for urea-assisted energy-saving hydrogen production

“…04-0784) 42–44 and Rh (JCPDS no. 05-0685), 29 and no additional diffraction peaks can be found, which indicates the successful formation of the AuRh alloy structure. Besides, the five obvious diffraction peaks at 38.53°, 44.67°, 64.90°, 77.91° and 82.14° of the P-mAuRh film are indexed to the (111), (200), (220), (311), and (222) planes of the face center cubic (fcc) Au–Rh alloyed crystal structure, respectively.…”

“…S8a,† the charge transfer resistance ( R ct ) of the catalyst is expressed in the form of curves with different diameters. 29 Obviously, the smallest R ct of P-mAuRh film/NF relative to others reveals that the addition of non-metallic P could accelerate the charge transfer rate during the HER, which is because the introduction of P enlarges the active area and utilization of host metal, and thus enhanced electrocatalytic activity is obtained. 57 Catalytic stability and durability are also crucial criteria for the performance of electrocatalysts.…”

“…28 Strategies for enhancing the electrocatalytic activity of Rh catalysts mainly focus on precisely engineering the electronic structure and the adsorption sites of the electrocatalysts by rational manipulation of their composition and structure. 29,30 It has previously been reported that the combination of chemically inert gold with other metals is conducive to boosting both the electrocatalytic activity and stability of catalysts. 31,32 Non-metal phosphorus (P), with a large atomic radius and strong electron-donating ability, can significantly tune the local electronic structure of the host catalyst, and thus facilitate oxygen/hydrogen desorption for favourable OER/HER catalysis.…”

Roles of Co Dopants in Electrocatalytic Hydrogen Evolution by N-Rich Carbon Nanotubes Grafted on Carbon Layers

“…Pt-based catalysts have exhibited excellent HER activity, 6,7 but their practical applications are limited by their scarcity and high cost. 8,9 Although some alternative HER catalysts based on the other noble metals are similar to or superior to Pt/C catalysts, 10 the high cost and the low abundance are still undesirable. On the contrary, catalysts based on non-noble transition-metal carbides, oxides, nitrides, sulfides, phosphides, and selenides have been reported to exhibit promising activity toward HER.…”