Highly Porous Carbon Flakes Derived from Cellulose and Nickel Phosphide Heterostructure towards Efficient Electrocatalysis of Oxygen Evolution Reaction

Abstract

This study delves into the pressing challenges of climate change and the escalating carbon dioxide (CO2) emissions by exploring hydrogen technology as a sustainable alternative. In particular, there is focus on nickel phosphide-based electrocatalysts, known for their promising performance in hydrogen evolution reactions (HERs) and oxygen evolution reactions (OERs). Therefore, here we have designed a facile strategy to deliver highly porous carbon flakes derived from cellulose fibers via carbonization at 850 °C, yielding highly porous structures and outstanding specific surface area (SSAcel_carb_850_act = 3164 m2/g) after activation. As-fabricated carbon was utilized as a support for Ni12P5 with an optimized mass ratio. Electrochemical testing revealed that the composite of Ni12P5 and carbon flakes with a ratio of 100:1, respectively, exhibited the most favorable kinetics for the oxygen evolution reaction (OER). Importantly, the durability tests of this sample demonstrated the most stable behavior and lowest potential change under high current density among the studied samples, making it a promising candidate in practical applications. Moreover, the analysis of electrocatalysts after an OER does not show any changes, indicating that the sample does not undergo undesired intermediate reactions and that unwanted products are not released, explaining its stable behavior. This provides a straightforward approach for creating a cellulose-derived composite with enhanced electroactivity and durability.

Renewable Carbonaceous Materials from Biomass in Catalytic Processes: A Review

“…In this study, Ni 12 P 5 _cellulose_1:100 displayed the lowest Tafel slope, indicating superior electrocatalytic efficiency compared with other composites. Interestingly, the Tafel slope decreased with increasing Ni 12 P 5 content, suggesting a change in the rate-determining step and improved reaction kinetics [153].…”

“…Mijowska et al investigate hydrogen technology in their study, specifically focusing on nickel phosphide-based electrocatalysts known for their effectiveness in HER and OER. They introduce a simple strategy involving the production of highly porous carbon flakes derived from cellulose fibers, exhibiting exceptional specific surface area (3164 m 2 /g) after activation at 850 • C. The resulting composite of Ni 12 P 5 and carbon flakes (100:1 ratio) demonstrates superior kinetics for the OER, outstanding durability, and stability under high current density, making it a promising candidate for practical applications [153]. As shown in Figure 8a, the Ni 12 P 5 _cellulose_1:100 sample demonstrated the smallest overpotential at 10 mA cm −2 current density (η = 338 mV) in comparison with other ratios.…”

Core–Shell CoS2@MoS2 with Hollow Heterostructure as an Efficient Electrocatalyst for Boosting Oxygen Evolution Reaction

“…Recently, transition-metal-based composites with earth-abundant sources and high efficiency have been proposed to substitute noble-metal catalysts. Many kinds of metal composites, including metal sulfides [12][13][14][15], metal phosphides [16,17], and metal oxides/hydroxides [18][19][20], have been demonstrated to show improved catalytic OER activity in an alkaline electrolyte. As confirmed by computational and experimental analyses, cobalt sulfides with a refined surface chemical state can be used as effective catalysts to facilitate the electrochemical reaction during the OER process [21,22].…”