Eco-synthesis of green silver nanoparticles using natural extracts and its application as co-catalyst in photocatalytic hydrogen production

• Published in: RSC advances 2024-09, Vol.14 (42), p.3136-3146
• Main Authors: Nguyen, Phuong N, Tran, Thao Quynh Ngan, Le, Khoa Hai, Khong, Diem T, Pham, Hoai Phuong, Dang, Quang V, Tran, Quang-Hieu, Nguyen, Tuan M, Nguyen Dang, Nam
• Format: Article
• Language: English
• Subjects: Carbon nitride; Catalysts; Catalytic activity; Chemical synthesis; Chemistry; Clean energy; Electron transfer; Green tea; Heterojunctions; Hydrogen evolution; Hydrogen production; Light irradiation; Luminous intensity; Nanoparticles; Optical properties; Photocatalysis; Photoelectric effect; Reducing agents; Silver; Surface plasmon resonance
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d4ra05675b

Green silver nanoparticles (AgNPs) were synthesized using natural extracts as reducing agents and were firstly applied as co-catalysts in low-intensity-visible-light driven photocatalytic hydrogen production (PH2P), which a solution for green energy sources and independence from fossil fuels. The as-prepared AgNPs possessed size in a few tens nanometers and exhibited surface plasmon resonance (SPR) effects in the 310-560 nm region. Depositing AgNPs on g-C 3 N 4 nanosheets broadened the visible absorption range, reduced electron-hole recombination, and increased electronic communication at the interface. g-C 3 N 4 /Ag demonstrated high PH2P efficiency, stability over three consecutive cycles, and a rapidly rising photocurrent under low-intensity visible light irradiation, although these features were not observed in g-C 3 N 4 alone. The H 2 evolution of g-C 3 N 4 /Ag_CC (CC: Cinnamomum camphora ), g-C 3 N 4 /Ag_GT (GT: green tea), and g-C 3 N 4 /Ag_PP (PP: pomelo peels) reached 252.6, 125.3 and 92.0 μmol g −1 at 180 min at the first cycle, respectively. Among them, g-C 3 N 4 /Ag_CC showed the highest photocatalytic activity, which may be attributed to the superior morphology, optical properties of AgNPs_CC, and efficient electron transfer from g-C 3 N 4 to AgNPs_CC. The SPR effect and Schottky barriers formed at the interface could contribute to enhancing the overall efficiency of the heterojunction photocatalysts. The results highlighted a crucial advancement toward H 2 production under low-intensity visible-light irradiation. Applying green AgNPs as co-catalysts in low-intensity-visible-light driven photocatalytic hydrogen production offers a solution for green energy sources and independence from fossil fuels.