Fabrication and Performance Evaluation of Pd‐Cu Nanoparticles for Hydrogen Evolution Reaction

Abstract

Herein, the effects of different types of surfactants including sodium dodecyl sulfate (SDS), cetyltrimethyl ammonium bromide (CTAB), and t‐octyl phenoxy polyethoxy ethanol (Triton X‐100, TX‐100) were presented on the hydrogen evolution reaction (HER) at the surface of carbon paste electrode (CPE) modified with Pd−Cu nanoparticles. Firstly, Cu nanoparticles with average diameters at about 80 nm were electro‐deposited at the CPE surface in H2SO4 solution containing CTAB and CuSO4 by potentiostatic method. Then, Pd−Cu bimetallic nanoparticles with diameters at about 75 nm were prepared through galvanic replacement reaction between PdII ions and Cu particles. The synthesized Cu nanoparticles were covered by CTAB in solution and surface tension of the nanoparticles were decreased, and consequently stabilized. Also, the surfactants play different roles on the HER depending on the electrode polarity and surface charges. The electro‐catalytic activity of the Pd−Cu/CPE and nano‐Cu/CPE towards HER was found to be highest in the presence of SDS. The effects of galvanic replacement reaction and type of surfactants on kinetic parameters of the HER such as cathodic electron transfer coefficient and exchange current density were comparatively investigated.

Galvanic replacement reaction to prepare catalytic materials

“…The 40% Sn‐doped Pd (Pd 0.6 Sn 0.4 ) exhibited a high electrochemically active surface area (488 cm 2 ), high exchange current density (114.63 mA cm −2 ), low Tafel slope (58 mV dec −1 ), and an overpotential of 68 mV to reach a current density of 10 mA cm −2 . Similarly, the Pd–Cu bimetallic NPs‐based carbon paste electrode (CPE) prepared through GRR also exhibited improved HER with the Volmer−Heyrovsky mechanism at its surface 100 . Furthermore, the surfactants such as sodium dodecyl sulfate (SDS), t‐octyl phenoxy poly ethoxy ethanol (Triton X‐100), and cetyl trimethyl ammonium bromide (CTAB) increased the current density of HER, with SDS providing the highest HER activity of Pd–Cu bimetallic NPs.…”

“…Similarly, the Pd-Cu bimetallic NPs-based carbon paste electrode (CPE) prepared through GRR also exhibited improved HER with the VolmerÀHeyrovsky mechanism at its surface. 100 Furthermore, the surfactants such as sodium dodecyl sulfate (SDS), t-octyl phenoxy poly ethoxy ethanol (Triton X-100), and cetyl trimethyl ammonium bromide (CTAB) increased the current density of HER, with SDS providing the highest HER activity of Pd-Cu bimetallic NPs. Thota et al reported that the HER activity of the bimetallic Ag/Ni heterostructures deposited on a flexible polyester film (overhead projector, OHP) could be optimized by varying the GRR time, resulting in different surface morphologies and varied ratios of silver and nickel within the deposit.…”