Environmentally Sustainable Synthesis of a CoFe₂O₄–TiO₂/rGO Ternary Photocatalyst: A Highly Efficient and Stable Photocatalyst for High Production of Hydrogen (Solar Fuel)

Abstract

Herein, a magnetically separable reduced graphene oxide (rGO)-supported CoFe 2 O 4 –TiO 2 photocatalyst was developed by a simple ultrasound-assisted wet impregnation method for efficient photocatalytic H 2 production. Integration of CoFe 2 O 4 with TiO 2 induced the formation of Ti 3+ sites that remarkably reduced the optical band gap of TiO 2 to 2.80 eV from 3.20 eV. Moreover, the addition of rGO improved the charge carrier separation by forming Ti–C bonds. Importantly, the CoFe 2 O 4 –TiO 2 /rGO photocatalyst demonstrated significantly enhanced photocatalytic H 2 production compared to that from its individual counterparts such as TiO 2 and CoFe 2 O 4 –TiO 2 , respectably. A maximum H 2 production rate of 76 559 μmol g –1 h –1 was achieved with a 20 wt % CoFe 2 O 4 - and 1 wt % rGO-loaded TiO 2 photocatalyst, which was approximately 14-fold enhancement when compared with the bare TiO 2 . An apparent quantum yield of 12.97% at 400 nm was observed for the CoFe 2 O 4 –TiO 2 /rGO photocatalyst under optimized reaction conditions. This remarkable enhancement can be attributed to synergistically improved charge carrier separation through Ti 3+ sites and rGO support, viz., Ti–C bonds. The recyclability of the photocatalyst was ascertained over four consecutive cycles, indicating the stability of the photocatalyst. In addition, it is worth mentioning that the photocatalyst could be easily separated after the reaction using a simple magnet. Thus, we believe that this study may open a new way to prepare low-cost, noble-metal-free magnetic materials with TiO 2 for sustainable photocatalytic H 2 production.

Novel P-n Li2SnO3/g-C3N4 Heterojunction With Enhanced Visible Light Photocatalytic Efficiency Toward Rhodamine B Degradation

“…Constructing visible light-responsive Li 2 SnO 3 -based heterojunction photocatalysts to make full use of sunlight is thus an important goal. This kind of system, where a heterojunction is formed between a visible light-and a UV light-responsive photocatalyst, has received some attention in recent years (Pan et al, 2012;Wu et al, 2017;Liu et al, 2018;Qiao et al, 2018;Wang et al, 2018a;Hafeez et al, 2019). For instance, ZnFe 2 O 4 /TiO 2 heterojunctions exhibited outstanding photocatalytic degradation of bisphenol A under visible light irradiation (Nguyen et al, 2019).…”

Porous Carbon Networks Decorated with Cobalt on CoFe2O4 as an Air‐Breathing Electrode for High‐Capacity Rechargeable Lithium‐Air Batteries: Role of Metallic Cobalt Nanoparticles

“…The peaks appeared at 3290 and 2160 cm −1 in all the samples correspond to the presence of O−H bond and H−O−H bending vibrations of the adsorbed water, whereas the peaks are seen at 1616, 1380 and 1052 cm −1 are ascribed to the stretching vibrations of C=O, C=C and C−H bonds, respectively. The peaks at 610 and 441 cm −1 in all three samples correspond to the intrinsic stretching vibrations of the Co 2+ ‐O at the tetrahedral site and the Fe 3+ ‐O at the octahedral site of the CoFe 2 O 4 , respectively …”

Hybrid material based on TiO2, CuBTC, and magnetic particles as a novel photocatalyst for MB removal

“…CuFe 2 O 4 nanoparticles were obtained using the facile co‐precipitation technique 45 . First, both Cu(NO 3 ) 2 .6H 2 O (0.004 mol, 1.184 g) and Fe(NO 3 ) 3 .9H 2 O (0.008 mol, 3.232 g) were poured simultaneously into a single‐neck flask before addition of 60 mL deionized water (DI) and stirring with a magnetic stirrer for 20 min.…”

“…However, the process of recovering these catalysts from the aqueous media after completion of the reaction is not completely known. The linking of magnetic particles with these catalysts may be the most suitable explanation for this issue 45–48 . Among the catalysts, copper ferrite (CuFe 2 O 4 ) is widely used in pollution decomposition applications because of its advantages such as environmental friendliness and the sufficient availability of copper 49,50 .…”