Electrocatalytic Pt-embedded ZIF-8 on nanocellulose-based flexible conductive electrodes for hydrogen evolution reaction

Abstract

Hydrogen fuel cell is a clean green energy device, but it is demanded valid conjugation between catalyst and substrate for generating the effective active site and ion transfer. Here, the hydrogen evolution reaction (HER) efficiency was investigated using Pt-embedded zeolitic imidazolate framework-8 (Pt@ZIF-8) electrocatalysts. Although the Pt content was only 2.8 wt%, the efficiency was equivalent to the reference catalyst (~ 40 wt% Pt in carbon); The reduction of Pt content improves cost performance and saves resources, making fuel cells more affordable. Furthermore, a flexible substrate consisting of electroconductive sulfonated polypyrrole and TEMPO-oxidized cellulose nanofiber film was found to be effective for embedding Pt@ZIF-8 electrocatalysts, acting as flexible and lightweight electrodes. Moreover, the generated hydrogen easily diffuses through the porous cellulose film. The fabricated electrocatalytic substrates are promising composite materials for hydrogen fuel cells, which consume significantly small amount of noble metal, making the renewable energy production more reasonable. Graphical abstract: [Figure not available: see fulltext.]