Novel torus shaped g-C3N4 photocatalysts

Abstract

Torus shaped g-C3N4 particles were created for first time via flame spray pyrolysis (FSP) process and tested for photocatalytic H2 production under visible light irradiation. It was found that the precursor dispersion concentration is important for the particles final morphology as diverse shapes can be obtained. It was established that the FSP process affects the surface functional groups, while the main g-C3N4 network is preserved. Despite the decrease of the SSA from 130.04–81.85 m2/g after the FSP, the H2 evolution rate was improved from 33.06–41.18 μmol/g/h. This phenomenon was concluded to be the result of surface defects decrease during the FSP process, which otherwise act as recombination sites inhibiting the electron transfer from g-C3N4 to the Pt. This study proposes an efficient one-step method for structural modification of g-C3N4 and provides new insight regarding the correlation between experimental conditions and shape of the obtained g-C3N4 particles.