Design of Electroactive Carbon Fibers Decorated with Metal and Metal‐Phosphide Nanoparticles for Hydrogen Evolution Technology

Abstract

The preparation of noble‐metal‐free electrode materials that enable the effective and economically viable hydrogen evolution reaction (HER) is proposed by using a needle‐less electrospinning method. Three transition metals (Ni, Co, Cu) capable of creation metal phosphides were stably incorporated into the carbon fibrous matrix. The electrode materials were prepared from low‐cost chemical reagents such as polyacrylonitrile, metal chlorides, and phosphoric acid. The embedded metal phosphides fundamentally influence the composition, microstructure, and porosity as evidenced by X‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses. The possible mechanisms for the formation and localization of nanoparticles were suggested. Linear sweep voltammetry, impedance spectroscopy, time of flight (TOF) calculation, and Tafel slope measurements in an acidic environment revealed that the highest electrocatalytic activity for HER was achieved in the carbon fibers decorated either with the cobalt/cobalt phosphide or copper/copper phosphide nanoparticles under heat treatment in a hydrogen atmosphere.

Methane Decomposition Over Modified Carbon Fibers as Effective Catalysts for Hydrogen Production

“…Based on methane adsorption, Demicheli et al developed the following equation for calculating the maximum deposition rate of carbon and the activity of the catalyst: and for activity: where k is the specific rate constant for the rate of carbon deposition (g/g cat h kPa),Kp is the equilibrium constant for the decomposition of methane (kPa), K H is the equilibrium hydrogen adsorption constant (kPa −0.5 ), k d is the specific velocity constant for velocity deactivation (h −1 ), t* is the time at which the rate of methane deposition reaches a maximum (h) and n is the number of active sites participating at the rate determining step, most frequently n = 7 [31,32]. The calculated maximum deposition rate of carbon and therefore the overall rate at time t is lower than that reported in the literature [22][23][24][25]. However, different experimental conditions, higher pressure, space velocities were used.…”

“…The modified fibrous samples were designed for the electrocatalytic production of hydrogen evolution reaction [23]. PAN-Polyacrylonitrile (Aldrich, Mw = 150,000 g/mol, DMF -N,N-dimethylformamide (Acros Organic, 99.8%), nickel chloride hexahydrate NiCl 2 × 6H 2 O (p.a.…”

Emerging Smart Micro/Nanofiber‐Based Materials for Next‐Generation Wound Dressings

“…The effect of electrical stimulation on human mesenchymal cell behavior was evaluated by applying external pulsed electrical potential, which demonstrated the unique efficacy of electrical stimulation and aligned fiber topography in promoting cell proliferation. Besides, inorganic conductive materials involving carbon‐based materials (e.g., carbon nanotubes (CNTs), [ 85 ] and graphene [ 90 ] ) and metal‐based materials (e.g., Au, [ 91 ] copper [ 92 ] and zinc oxide (ZnO) [ 93 ] ) have been introduced to develop electroactive fibers. As a typical example, composite nanofiber yarns based on poly(p‐dioxanone) biopolymer and CNTs were developed by a modified electrospinning yarn‐forming apparatus.…”

Electronic modulation and interface engineering of electrospun nanomaterials‐based electrocatalysts toward water splitting

“…As discussed in the electronic modulation to improve HER performance, some of the electrocatalysts are CNFs‐based nanomaterials 83‐112 . It is well known that the electrospinning technique is a facile and versatile strategy to prepare functional electrocatalyst embedded in CNFs.…”