Ultrafine Ag Nanoparticles as Active Catalyst for Electrocatalytic Hydrogen Production

Abstract

Ag nanoparticles with different sizes were produced by laser ablation in liquid (PLAL) through tuning laser energy. As the catalyst for hydrogen evolution reaction (HER) in acidic medium, Ag nanoparticles show strong size-dependent activity, and the smallest Ag nanoparticles with average size of 3 nm display a low overpotential of 96 mV at 10 mA cm À 2 and Tafel slope of 76.10 mV dec À 1 , being superior to Ag foil and commercial Ag powder. The excellent performance is attributed to the large exposed surface, low coordination number, moderate hydrogen adsorption energy, and low charge transfer resistance.

Preparation of Ag nanoparticles by spark ablation in gas as catalysts for electrocatalytic hydrogen production

“…The electrocatalytic HER improvement is mainly attributed to the reduction in the size of Ag nanoparticles along with the increase in the carrier gas ow rate, which causes Ag nanoparticles to have a larger surface area, exposing more surface unsaturated coordination atoms, including edge and corner atoms, and facilitating the adsorption of intermediates. 6,13,29 By comparing the LSV curves obtained at different deposition times with a xed carrier gas ow rate (5 L min À1 ), the HER overpotential showed a decreasing trend at rst and then increasing, as shown in Fig. 5d.…”

“…5f), which is attributed to the nature of the Ag metal itself, which has a weak capacity to absorb H*. 6 Thus, the catalytic activities of the samples are indeed signicantly improved by reasonably tuning the deposition time.…”

“…5,27 On the contrary, Ag possesses abundant reserves, low cost and the highest conductivity in all metallic elements, but its d 10 electronic structure results in weak intermediate H* adsorption and poor HER performance in acidic media. 13,28,29 Therefore, many efforts have been devoted to regulating pure Ag, including increasing its surface area, 29 creating more unsaturated coordination atoms 6 and introducing tensile stress 13 to cause upshi of the d-band center, so that the HER performance of Ag can approach or exceed that of commercial Pt and make Ag a potential alternative for Pt. 30 Therefore, combined with the characteristics of the SAG method, it is feasible to prepare Ag nanoparticles with various features, such as small size and stacking fault to adjust the d-band electronic structure of Ag and thus improve the acidic HER performance.…”

“…30 Therefore, combined with the characteristics of the SAG method, it is feasible to prepare Ag nanoparticles with various features, such as small size and stacking fault to adjust the d-band electronic structure of Ag and thus improve the acidic HER performance. 6,29 Herein, Ag nanoparticles with high purity and clean surface are prepared by the SAG method. Carbon bers serve as a platform for the in situ deposition of Ag nanoparticles to suppress the aggregation of Ag nanoparticles and improve charge transfer.…”

Editorial: Electrocatalysis ‐ From Batteries to Clean Energy Conversion

“…reports the in situ diffuse reflectance infrared Fourier transform spectroscopy, quasi in situ X‐ray photoelectron spectroscopy and near‐edge absorption fine structure to study the water dissociation mechanism promoted by the two‐dimensional conjugated polymer during the photocatalytic process . Xi‐Wen Du's group reports the origin of Ag particles’ excellent HER performance according to the density functional theory calculations, which is the moderate hydrogen adsorption . The researchers will greatly benefit from the in‐depth understanding of catalysts, precise performance analysis and reaction mechanism exploration by a combination of in situ techniques and theoretical simulation.…”