Lignin-assisted alloying engineering of CoNiRu trimetallic nano-catalyst for effective overall water splitting

The development of inexpensive and robust bifunctional electrocatalysts for hydrogen evolution reactions (HER) and oxygen evolution reactions (OER) was crucial for renewable energy systems. Herein, a novel strategy for preparing CoNiRu alloy nano-electrocatalyst capsulated by nitrogen-doped biochar (CoNiRu@NLC) using carboxymethylated lignin macromolecules was proposed. CoNiRu@NLC exhibited excellent HER and OER performance, and the overall water splitting voltage was only 1.47 V at 10 mA/cm(2) with excellent catalytic stability, which was superior to the noble metal catalysts Pt/C || RuO2. Theoretical calculations confirmed the strong electron interaction between CoNiRu alloy and carbon layer, and XPS patterns proved that the electrons transfer from Ru to CoNi, significantly boosted the electrocatalytic activity. This study demonstrated the importance of lignin-driven alloying on enhancing catalytic performance and provided a concept for the development of high-efficiency catalysts and high-value utilization of polyphenol biomass.

Automated summary

This study proposed a novel strategy for preparing CoNiRu alloy nano-electrocatalyst through nitrogen-doped biochar encapsulation. The CoNiRu@NLC catalyst exhibited excellent performance in both HER and OER reactions, with a low overall water splitting voltage and superior stability compared to noble metal catalysts. Theoretical calculations and experimental results confirmed the crucial role of electron interaction between the alloy and the carbon layer in boosting electrocatalytic activity. The study demonstrated the importance of lignin-driven alloying in enhancing catalytic performance.