Synthesis of <scp>MCM</scp>‐41 and <scp>SBA</scp>‐15 from rice husk silica and their carbon replicas for hydrogen adsorption

Abstract BACKGROUND Rice husk, an abundant agricultural by‐product, presents a promising renewable silicon source for producing carbon‐based materials through sustainable and eco‐friendly approaches. Among emerging clean energy solutions, hydrogen storage remains a critical challenge for the practical deployment of hydrogen energy systems. This study explores the use of rice husk‐derived silica to synthesize mesoporous nanostructured silicon materials and their corresponding carbon replicas. The goal is to develop efficient materials for hydrogen adsorption, with performance surpassing that of other biomass‐derived carbons synthesized under comparable conditions – thereby offering a competitive and sustainable solution for hydrogen storage. RESULTS A cost‐effective, sustainable synthesis route was developed to produce siliceous templates MCM‐41 and SBA‐15 using cetyltrimethylammonium bromide and Pluronic P123 as surfactants. Their carbon replicas – rice husk ash (RHA)‐MCM‐41 and RHA‐SBA‐15 – were fabricated via a nanocasting method employing sucrose as a carbon source. The resulting materials were characterized using X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption–desorption techniques. Notably, the synthesized mesoporous carbons, RHA‐CMK‐3 and RHA‐RMCM‐41, exhibited high surface areas ranging from 800 to 1400 m 2 g −1 and featured both mesoporous and microporous structures. CONCLUSION The synthesized carbon replicas demonstrated significant hydrogen adsorption capabilities. Among them, RHA‐CMK‐3 showed the highest hydrogen storage performance, reaching 3.6 wt% at 196.15 °C and 10 bar. These findings highlight the potential of rice husk‐derived nanostructured carbons as efficient and sustainable materials for hydrogen storage applications. Moreover, the obtained materials exhibit hydrogen adsorption capacities surpassing those of other biomass‐derived carbons synthesized under similar conditions, reinforcing their competitive advantage for energy storage solutions. © 2025 Society of Chemical Industry (SCI).