Synthesis of Ilmenite Nickel Titanite-Supported Carbon Nanofibers Derived from Polyvinylpyrrolidone as Photocatalyst for H2 Production from Ammonia Borane Photohydrolysis

Abstract

The present study involves the synthesis of photocatalytic composite nanofibers (NFs) comprising ilmenite nickel titanite-supported carbon nanofibers (NiTiO3/TiO2@CNFs) using an electrospinning process. The photocatalytic composite NFs obtained were utilized in hydrogen (H2) production from the photohydrolysis of ammonia borane (AB). The experimental findings show that the photocatalytic composite NFs with a loading of 25 mg had a good catalytic performance for H2 generation, producing the stoichiometric H2 in 11 min using 1 mmol AB under visible light at 25 °C and 1000 rpm. The increase in catalyst load to 50, 75, and 100 mg leads to a corresponding reduction in the reaction time to 7, 5, and 4 min. The findings from the kinetics investigations suggest that the rate of the photohydrolysis reaction is directly proportional to the amount of catalyst in the reaction system, adhering to a first-order reaction rate. Furthermore, it was observed that the reaction rate remains unaffected by the concentration of AB, thereby suggesting a reaction of zero order. Increasing the reaction temperature results in a decrease in the duration of the photohydrolysis reaction. Furthermore, an estimated activation energy value of 35.19 kJ mol−1 was obtained. The composite nanofibers demonstrated remarkable and consistent effectiveness throughout five consecutive cycles. The results suggest that composite NFs possess the capacity to function as a feasible substitute for costly catalysts in the process of H2 generation from AB.

Photocatalytic dehydrogenation of ammonia borane over Ti3C2/MOF-supported Pd-doped Co nanoparticles

“…54 Subsequently, hydroxyl radicals were generated through oxidizing water molecules by the photogenerated holes. Notably, the AB molecule containing a B–N coordination bond is an electron donor–acceptor complex, 57,58 implying that the B–N bond is weaker than the covalent bond. It is well known that during AB hydrolytic dehydrogenation over metal NPs, AB was adsorbed onto metal NPs to be activated, and thus the B–N bond was disrupted by the attack of water molecules to release hydrogen.…”

A Recent Review of Electrospun Porous Carbon Nanofiber Mats for Energy Storage and Generation Applications

“…The unique properties of electrospun porous carbon nanofibers, such as their large surface area, excellent electrical conductivity, and tunable porosity, make them attractive candidates for catalytic applications [116]. For example, electrospun porous carbon nanofibers can be used as catalysts in various electrochemical reactions such as oxygen reduction reactions (ORRs), hydrogen evolution reactions (HERs), and oxygen evolution reactions (OERs) [117]. The high electrical conductivity and large surface area of nanofibers facilitate efficient charge transfer and enhance catalytic activity.…”