Modification of Carbon Nanotubes via Birch Reaction for Enhanced HER Catalyst by Constructing Pearl Necklace‐Like NiCo₂P₂–CNT Composite

Abstract

Combining transition metal phosphides (TMPs) with carbon nanotubes (CNTs) is a promising and proven approach to enhance their performance in the electrochemical hydrogen evolution reaction (HER), due to the excellent conductivity and stability of CNTs. Generally, the deep oxidation of CNTs to form oxygen‐containing groups on their surface is indispensable before combining them with TMPs. However, such approaches inevitably introduce a large number of defects to CNTs and apparently decrease their stability and electrical conductivity. Hence, fabricating TMP–CNT composites which does not come at the expense of CNTs' high electrical conductivity is quite desirable. In this work, alkylated CNTs (named as ACNT) functionalized via the Birch reaction are used to prepare the pearl necklace‐like NiCo2P2–ACNT composites for electrocatalysts toward HER in acidic and alkaline conditions, respectively. The X‐ray photoelectron spectroscopy, transmission electron microscope, and Fourier transform infrared spectroscopy characterizations indicate that the ACNTs are well modified with functional groups and keep their structural integrity, thereby maximizing their excellent conductivity. Compared to bare NiCo2P2 and the NiCo2P2–CNT composites prepared with mildly oxidized CNTs and deeply oxidized CNTs, the NiCo2P2–ACNTs show far better HER performance and much faster kinetics.

Rational Design of Better Hydrogen Evolution Electrocatalysts for Water Splitting: A Review

“…It is generally believed that modifying the substrates with functional groups enhanced the electrocatalytic activity of the composites while simultaneously obtain more exposed active sites. [ 157 , 158 , 159 ] Common functional groups are halogen atoms, [ 160 ] alcohols, aldehydes, carboxylic acids, and so on. Investigation on the impact of functionalization (multiwall carbon nanotubes) for Pt single‐atom and cluster catalyst (denoted as Pt/f‐MWCNTs) prepared via photodeposition possessed a higher mass activity of 18.16 A mg Pt −1 @‐0.05V.…”

Molybdenum and cobalt co-doped VC nanoparticles encapsulated in nanocarbon as efficient electrocatalysts for the hydrogen evolution reaction

“…14,15 However, the traditional method of preparing VC is generally high-temperature treatment, 16 which will inevitably lead to particle agglomeration, so that the numbers of catalytic active sites are reduced, and the catalytic activity of the VC-based hydrogen evolution electrocatalyst reported so far needs to be improved urgently. According to previous work, to ameliorate the electrocatalytic performance, the following three major routes can be adopted: (1) improving the intrinsic activity of catalysts, such as via metal element doping and non-metal element doping; (2) increasing the number of active sites, such as via building unique nanostructures (like nanoparticles, 17,18 nanosheets, [19][20][21] nanotubes, 22,23 core-shell nanoarrays 24 etc. ); and (3) improving electrical contact of active sites, such as via adding conductive substrates (mainly including carbon and metal substrates).…”

Necklace‐Like Nanostructures: From Fabrication, Properties to Applications

“…Inorganic NPs such as metals (e.g., Au, Ag, Cu, and Co), [34][35][36][37][38][39][40][41][42][43][44][45] metal oxides (e.g., TiO 2 , Fe 3 O 4 , Co 3 O 4 , CuO, ZnO, In 2 O 3 , NiFe 2 O 4 , BiFeO 3 , and PbTiO 3 ), [21,[46][47][48][49][50][51][52][53] hydroxides (e.g., Cd(OH) 2 ), [54] metal chalcogenides (e.g., CdS, Cu 2 S, ZnS, Bi 2 S 3 , CdSe, In 2 Se 3 , and Ag 2 Te), [55][56][57][58][59] and other nonmetallic inorganic NPs (such as carbon, [60] silica, [61] silicon, [62,63] and AlN [64,65] ) have been successfully crafted into inorganic mono-component NNs. Inorganic multicomponent NNs (e.g., Cu/Pt, [35] Ni/Ru, [31] Pd/Au, [66] CuO/NiO, [67] CdO/CdS, [68] Ag/AgCl, [69] Au/Fe 3 O 4 , [18] Pt/CeO 2 , [70] TiO 2 /SnO 2 , [26] TiO 2 /Co 3 O 4 , [71] NiCo 2 P 2 , [72] Pt/Ru/SnO 2 , [28] and BaTiO 3 @TiO 2 …”