Enhanced solar hydrogen production by template-free oxygen doped porous graphitic carbon nitride photocatalysts. (December 2022)

• Record Type: Journal Article
• Authors: Pandi, Kavitha; Rajan, Aswathy; Dhileepan, M.D.; Sekar, Karthikeyan; Neppolian, Bernaurdshaw
• Is Part Of: Materials today chemistry. Volume 26(2022)
• Publication Date: 2022-12
• Subjects: Water splitting -- Surface plasmon resonance -- Charge recombination -- Polycondensation -- Mesoporous; Chemistry -- Periodicals; Materials -- Research -- Periodicals; Materials science -- Periodicals; Chemistry; Materials -- Research; Electronic journals; Periodicals; 660.282
• DOI: 10.1016/j.mtchem.2022.101173
• Languages: English
• ISSNs: 2468-5194

Abstract

Abstract: In this work, a new strategy has been developed to synthesis template-free porous oxygen doped g-C3 N4 nanorods by sulfur–assisted ultrasound followed by thermal polymerization method. As a result of a highly porous g-C3 N4 nanorod (CNRS) with a surface area of 62 m 2 /g was observed, which is a factor of ∼3 times higher than bulk g-C3 N4 (CNB). Importantly, N–O and an increased number of C=O bonds were observed in CNRS after sulfur-assisted treatment due to oxygen doping. Further, in-situ deposition of Pt has suppressed N–O and C=O bonds by forming divalent Pt, which could favor fast charge carrier transport. This proved by time-resolved photoluminescence measurement where relaxiation time of charge carrier in shallow-trap and deep-trap states significantly reduced to 2.1 and 8.5 ns respectively. As a result, a maximum H2 production rate of 5.5 mmol/h/g is achieved in solar light, which is ∼30 times higher than CNB. This significant enhancement in photocatalytic performance is owing to superior visible region harnessing properties, large specific surface area, and high porosity in oxygen doped porous g-C3 N4 nanorods. We report, simple strategy and a new path for an effective designing of porous g-C3 N4 nanorod photocatalyst by template-free and non-hazardous chemicals. Highlights: A new strategy template-free synthesis of oxygen doped g-C3 N4 nanorods (CNRS). Sulfur–assisted ultrasound followed by thermal polymerization method. Achieved highly porous CNRS with surface area of ∼3 times higher than bulk g-C3 N4 . Maximum H2 production rate of 5.5 mmol/h/g, which is ∼30 times higher than bulk. An excellent performance due to combined effects with superior charge carrier transportation.