A Polyoxoniobate/g-C3N4 Nanoporous Material with High Adsorption Capacity of Methylene Blue from Aqueous Solution

Abstract

A polyoxoniobate/g-C3N4 nanoporous material with functional groups has been synthesized by using carbon nitride (g-C3N4) and hexaniobate (K8Nb6O19·10H2O, abbreviated as NbO) as precursors. The structure and compositions of the as-prepared nanomaterials were characterized by XRD, FT-IR, FESEM, TEM, and XPS. These two kinds of materials interact with each other forming a hybrid composite, which can be used as an adsorbent for removing a cationic dye (methylene blue, MB) from wastewater with excellent adsorption capacity. Furthermore, parameters that can affect adsorption process including initial dye concentration, pH and temperature were investigated by bath adsorption experiments. The results indicated that the maximum adsorption capacity of NbO/g-C3N4 can reach up to 373.1 mg g−1. Moreover, the equilibrium experiment data fitted Langmuir isotherm well and the adsorption kinetics showed that the pseudo second order model can satisfyingly described MB adsorption kinetics. The thermodynamic analysis indicated that the adsorption was endothermic and spontaneous.

Preparation of Carboxymethyl Cellulose-Based Macroporous Adsorbent by Eco-Friendly Pickering-MIPEs Template for Fast Removal of Pb2+ and Cd2+

“…The adsorption process was analyzed by the Langmuir (Equation 2) and Freundlich isotherm models (Equation 3) (Gan et al, 2018), and the equations are shown as follows:…”

Highly Efficient Adsorption of Phenylethanoid Glycosides on Mesoporous Carbon

“…In addition, the 1/n value of PhGs was calculated to be 0.22, which was <0.5. It indicated that the adsorption of the PhGs on the CMK-3 could take place easily (Fu et al, 2007; Gan et al, 2018). This indicated that the adsorption of PhGs on CMK-3 was not completely a physical adsorption process.…”

Toward Exploiting the Behavior of Niobium-Containing Mesoporous Silicates vs. Polyoxometalates in Catalysis

“…Moreover, they can also be simply transformed to reactive forms by applying light and electricity (Gumerova and Rompel, 2018 ). The applications of polyoxometalate clusters as catalysts are many and varied, nonetheless they include mostly green H 2 O 2 -based epoxidation systems (Zhou et al, 2015 ), catalytic approaches to sustainable splitting of water (Long et al, 2010 ), and also photocatalysis in various photoredox systems e.g., the oxidation of alkanes, alkenes or alcohols as well as in the light-induced mineralization of several organic and inorganic contaminants (Shen et al, 2009 ; Streb, 2012 ; Wang et al, 2017 ; Gan et al, 2018 ; Li et al, 2018 ).…”

“…There are already examples of other than niobium-based polyoxometalates (Lefebvre, 2013 ). Only recently a functionalized polyoxoniobate/g-C 3 N 4 nanoporous material has been synthesized with carbon nitride (g-C 3 N 4 ) and hexaniobate (K 8 Nb 6 O 19 ·10H 2 O) as starting materials (Gan et al, 2018 ).…”