Enhanced Hydrogen Evolution by Deep-Sea Marine Sediment Photocatalysts: Surface Modification with Bismuth Subnitrate

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Ismunandar, Eko Siswanto, Slamet Wahyudi, Willy Satrio Nugroho, Abid Fahreza Alphanoda, I.N.G. Wardana

2026 Results in Engineering Vol. 29 Article Cited by 1

Abstract

Deep-sea marine sediments are abundant natural materials rich in iron oxides, offering a sustainable platform for green hydrogen production through photocatalysis. In this study, deep sea marine sediment samples collected from various ocean depths were examined as photocatalysts for the hydrogen evolution reaction (HER). Surface morphology and chemical composition were characterized using XRD, SEM-EDX, and FTIR, revealing the presence of hematite and goethite as active mineral phases. To enhance photocatalytic performance, surface modification was conducted using bismuth subnitrate. The modified samples demonstrated improved hydrogen generation, attributed to enhanced charge separation and increased active surface sites. Among all samples, the AL-6 sediment modified with bismuth subnitrate exhibited the highest hydrogen evolution rate under UV-A irradiation, achieving 3873 µmol g⁻¹, which represents a 3.4-fold enhancement compared to the AL-13+BBN sample. This quantitative improvement underscores the critical role of the AL-6 microstructure and its synergistic interaction with bismuth species in promoting charge separation and catalytic efficiency providing a green and cost-effective approach for hydrogen production. © 2025 The Authors.

Affiliations

Department of Mechanical Engineering, Brawijaya University, East Java, Malang, 65145, Indonesia; Departement of Fisheries Machinery, Jakarta Technical University of Fisheries, Ministry of Marine Affairs and Fisheries, Republic of Indonesia, 12520, Indonesia; Department of Mechanical Engineering, Pancasila University, Jakarta, 12630, Indonesia