Low-frequency ultrasound assisted synthesis of an aqueous aluminium hydroxide decorated graphitic carbon nitride nanowires based hybrid nanofluid for the photocatalytic H2 production from Methylene blue dye

Abstract

An aqueous Aluminium Hydroxide [Al(OH)3] decorated Graphitic Carbon Nitride [g-C3N4] nanowires based hybrid nanofluid has been fabricated using the two-step method. Where, both the nanoparticles are synthesized separately and dispersed throughout the base fluid with the aid of ultrasonic cavitation technique. The hybrid nanofluid photocatalytic performance has been compared with Al(OH)3 – (g-C3N4) hybrid photocatalyst. After the preparation, the hybrid nanofluid and nanoparticles properties are systematically characterized. The FESEM results confirmed the effectiveness of the low frequency (30 kHz) ultrasonication in coating the Al(OH)3 nanoparticle on to the g-C3N4 surface. The larger BET specific surface area (80.45 m2/g) and the lower bandgap energy (2.35 eV) assured the enhanced photocatalytic H2 production from the degradation of Methylene Blue dye. Moreover, the obtained 0.5 vol% Al(OH)3–(g-C3N4)/H2O hybrid nanofluid produced about 6 times higher H2 than that of Al(OH)3 – (g-C3N4) hybrid photocatalyst. Even after 4 cycles, the hybrid nanofluid showed only 1% decrement in the photocatalytic performance. This study of replacing photocatalyst with the hybrid nanofluid delivers a sustainable route to harvest the H2 from photocatalytic degradation of the industrial pollutants in the presence of visible light.