Co_(3)S_(4)-pyrolysis lotus fiber flexible textile as a hybrid electrocatalyst for overall water splitting

Electrocatalytic overall water splitting(OWS),a pivotal approach in addressing the global energy crisis,aims to produce hydrogen and oxygen.However,most of the catalysts in powder form are adhesively bounding to the electrodes,resulting in catalyst detachment by bubble generation and other uncertain interference,and eventually reducing the OWS performance.To surmount this challenge,we synthesized a hybrid material of Co_(3)S_(4)-pyrolysis lotus fiber(labeled as Co_(3)S_(4)-p LF)textile by hydrothermal and hightemperature pyrolysis processes for electrocatalytic OWS.Owing to the natural LF textile exposing the uniformly distributed functional groups(AOH,ANH_(2),etc.)to anchor Co_(3)S_(4)nanoparticles with hierarchical porous structure and outstanding hydrophily,the hybrid Co_(3)S_(4)-p LF catalyst shows low overpotentials at 10 m A cm^(-2)(η_(10,HER)=100 m Vη_(10,OER)=240 mV)alongside prolonged operational stability during electrocatalytic reactions.Theoretical calculations reveal that the electron transfer from p LF to Co_(3)S_(4)in the hybrid Co_(3)S_(4)-p LF is beneficial to the electrocatalytic process.This work will shed light on the development of nature-inspired carbon-based materials in hybrid electrocatalysts for OWS.

Unravelling the critical role of surface Nafion adsorption in Ptcatalyzed oxygen reduction reaction by in situ electrical transport spectroscopy

Solid-state ionic conductor is a vital part in all electrochemical energy conversion devices. As a widely-applied protonconducting polymer and stabilizer for electrode preparation, Nafion has key applications in electrochemical devices operated under acidic conditions. Specific adsorption of Nafion on the catalyst surface is considered to result in partial loss of intrinsic activity in reactions such as oxygen reduction reaction(ORR), due to its comprehensive occupation of active sites. Many in situ characterization methods such as voltammetric fingerprinting and spectroscopic approaches have been used to explore the dynamic adsorption of Nafion on the electrode surface. However, most of current efforts have been focused on the behaviors of Nafion itself, with little attention paid to its effects on the adsorption of surface intermediates. Here, we employed the in situ electrical transport spectroscopy(ETS) to investigate Nafion adsorption on Pt catalysts and its effects on the ORR intermediates.Our findings suggest that specific adsorption of Nafion results in the increased coverage of oxygen intermediates with weaker adsorption strength, which in turn plays a critical role in the reaction selectivity. The successful application of ETS on the dynamic characterization of reaction intermediates provides a novel perspective for catalyst design in ORR-related applications in future sustainable chemistry.