Magnetically Separated meso-g-C₃N₄/Fe₃O₄: Bifuctional Composites for Removal of Arsenite by Simultaneous Visible-Light Catalysis and Adsorption

Abstract

Bifunctional mesoporous g-C3N4/Fe3O4 composites were prepared and used for the simultaneous visible-light catalysis and adsorption of arsenic from aqueous solution. The as-prepared composites were characterized by wide-angle X-ray powder diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, a vibrating sample magnetometer, and Brunauer–Emmett–Teller surface analysis. Experimental results showed that meso-g-C3N4/Fe3O4 composites could oxidize As­(III) to As­(V), which was in turn effectively removed by the composites. The photocatalytic activity was significantly enhanced by the synergistic effect between g-C3N4 and Fe3O4. In addition, a reasonable visible-light catalytic oxidation mechanism of As­(III) was investigated.

Enhanced photoreduction degradation of polybromodiphenyl ethers with Fe3O4-g-C3N4 under visible light irradiation

“… 20 The XRD of Fe 3 O 4 exhibits six diffraction peaks indexed as (220), (311), (400), (422), (511) and (440). 19,23 All of the hybrids of FeOCN- x show the characteristic peak of g-C 3 N 4 and Fe 3 O 4. With increasing Fe 3 O 4 content, the relative diffraction intensity of g-C 3 N 4 gradually decreases following the diffraction intensity of Fe 3 O 4 and increasing in the FeOCN- x samples.…”

“…g-C 3 N 4 was prepared by thermal polycondensation of dicyandiamide according to the reported procedure. 25 Fe 3 O 4 -g-C 3 N 4 hybrids were prepared as follows: 19 1.0 g of g-C 3 N 4 powder was added to 250 mL of ethanol/water (1 : 2, v/v) solution by ultrasonic treatment for 5 h. A certain amount of FeCl 3 ·6H 2 O and FeCl 2 ·4H 2 O were dissolved in the deionized water and then added to the g-C 3 N 4 suspension. Aqueous ammonia was added to the mixture under stirring at 80 °C.…”

“… 18–22 For example, Ye et al 18 reported that Fe 3 O 4 -g-C 3 N 4 showed an improved efficiency for degradation of dyes under visible light irradiation and easy recycling use. Chi et al 19 found that Fe 3 O 4 -g-C 3 N 4 had a high photocatalytic activity performance for the oxidization of As( iii ) to As( v ) and could be easily recovered by magnetism. Compared with the extensive research on the photocatalytic oxidation ability of Fe 3 O 4 -g-C 3 N 4 , the photocatalytic reduction performance of Fe 3 O 4 -g-C 3 N 4 , 22 especially on degradation of the halogen organic pollutants is quite rare, which may reveal another important application for Fe 3 O 4 -g-C 3 N 4 .…”

A magnetically separable and recyclable g-C3N4/Fe3O4/porous ruthenium nanocatalyst for the photocatalytic degradation of water-soluble aromatic amines and azo dyes

“…Further, the separation of the catalyst can be made simpler by incorporating a magnetic support. 46,[59][60][61][62][63][64][65][66][67][68] A potentially efficient photocatalytic system would possess the combined advantages of g-C 3 N 4 , porous RuNP and magnetic Fe 3 O 4 NP. Considering this hypothesis, herein, we demonstrate the development of a ruthenium-based magnetic g-C 3 N 4 /Fe 3 O 4 /p-RuNP nanocomposite system and investigate its photocatalytic behaviour towards the decomposition of water-soluble aromatic amines and azo dyes from water bodies.…”

Synthesis of Flower-Like g-C3N4/BiOBr and Enhancement of the Activity for the Degradation of Bisphenol A Under Visible Light Irradiation

“…However, pure g-C 3 N 4 has poor photocatalytic performance regarding limited organic pollutants due to its low quantum efficiency, which limits its practical applications (Liu et al, 2010; Yan et al, 2010). So far, great efforts have been taken to improve the photocatalytic performance of g-C 3 N 4 , such as metal and nonmetal elements doping (Zhang et al, 2009; Liu et al, 2010; Wang et al, 2010), designing different morphology (Groenewolt and Antonietti, 2005; Vinu et al, 2005; Goettmann et al, 2006; Lu et al, 2014), constructing heterostructure with other semiconductor photocatalysts such as ZnO (Kuang et al, 2015), Cu 2 O (Peng et al, 2014), MoS 2 (Li et al, 2014), Fe 3 O 4 (Chi et al, 2016), Bi 2 WO 6 (Wang et al, 2017). Actually, modified g-C 3 N 4 shows excellent photocatalytic properties because the modification of g-C 3 N 4 with other photocatalysts promotes the separation of photogenerated carries.…”