New Insights into the Surfactant-Assisted Liquid-Phase Exfoliation of Bi2S3 for Electrocatalytic Applications

Abstract

During water electrolysis, adding an electrocatalyst for the hydrogen evolution reaction (HER) is necessary to reduce the activation barrier and thus enhance the reaction rate. Metal chalcogenide-based 2D nanomaterials have been studied as an alternative to noble metal electrocatalysts because of their interesting electrocatalytic properties and low costs of production. However, the difficulty in improving the catalytic efficiency and industrializing the synthetic methods have become a problem in the potential application of these species in electrocatalysis. Liquid-phase exfoliation (LPE) is a low-cost and scalable technique for lab- and industrial-scale synthesis of 2D-material colloidal inks. In this work, we present, to the best of our knowledge, for the first time a systematic study on the surfactant-assisted LPE of bulk Bi2S3 crystalline powder to produce nanosheets (NSs). Different dispersing agents and LPE conditions have been tested in order to obtain colloidal low-dimensional Bi2S3 NSs in H2O at optimized concentrations. Eventually, colloidally stable layered nano-sized Bi2S3 suspensions can be produced with yields of up to ~12.5%. The thus obtained low-dimensional Bi2S3 is proven to be more active for HER than the bulk starting material, showing an overpotential of only 235 mV and an optimized Tafel slope of 125 mV/dec. Our results provide a facile top-down method to produce nano-sized Bi2S3 through a green approach and demonstrate that this material can have a good potential as electrocatalyst for HER.

Water-Based Bi2S3 Nano-Inks Obtained with Surfactant-Assisted Liquid Phase Exfoliation and Their Direct Processing into Thin Films

“…− group forms a H-bond with water and stabilizes the exfoliated layers [25]. Our previous work also proves the possibility of exfoliation of Bi 2 S 3 with SDS [26]. Moreover, surfactants with a similar structure to SDS but different functional groups have been reported in LPE, such as sodium dodecylbenzene sulfonate (SDBS).…”

“…Specifically, the intensity ratio of Ag mode and B1g mode is calculated to determine whether the samples were exfoliated [19,40]. In bulk Bi2S3, the Ag/B1g ratio is 1.68 [26], while for all the 4 displays the Raman spectra of Bi 2 S 3 samples with all the surfactants. It is possible to identify two main active modes, namely the B 1g and A g Raman modes, in all the samples.…”

Liquid Phase Exfoliation of 2D Materials and Its Electrochemical Applications in the Data-Driven Future

“…Wang et al conducted a study where they explored the impact of the initial bulk Bi 2 S 3 concentration in surfactant-assisted LPE while keeping other factors constant. 195 They observed that exfoliation yield remained consistently around 12% within the range from 0.33 mg mL −1 to 1.33 mg mL −1 of initial Bi 2 S 3 concentration. In this range, the exfoliation yield increased linearly with rising concentrations.…”

“…(a) Exfoliation yield (black line) and concentration of LPE Bi 2 S 3 in SC/H 2 O suspensions (red line) after 3 h of sonication at different initial bulk Bi 2 S 3 concentrations. Reprinted under the terms of the CC-BY 4.0 license from ref . Copyright 2023 MDPI.…”

Synergistic effect of a bamboo-like Bi2S3 covered Sm2O3 nanocomposite (Bi2S3–Sm2O3) for enhanced alkaline OER

“…34 To catalyze the OER, sulfur in Bi 2 S 3 integrates the layered structure and active species in the matrix with their direct and indirect roles depending on the content of sulfur ions in the matrix. 35 In the OER, exposed S vacancies and atoms on the Bi 2 S 3 plane and edges accelerate the OER activity directly, while when metals Bi and Sm act as active sites for the reaction the sulfur atom provides sites for the adsorption and desorption of radicals and catalyzes the OER activity indirectly. 36 In addition, localized and migratory 3d sulfide electrons in the Bi 2 S 3 hybrid with 3s and 3p sulfide electrons sustain the neighbor's cations in different configurations (trigonal, tetrahedral, octahedral, etc. )…”