Exfoliated Graphitic Carbon Nitride Nanosheets/Gold Nanoparticles/Spherical Montmorillonite Ternary Porous Heterostructures for the Degradation of Organic Dyes

Abstract

Water-soluble organic carcinogenic pollutants have become a serious threat to both health and environment. Here, porous ternary spherical montmorillonite/exfoliated graphitic carbon nitride nanosheets/gold nanoparticles (SMt/g-C 3 N 4 /Au NPs) heterostructures were facile and green synthesized through a polydopamine chemistry method. These involved the coating of porous SMt with exfoliated g-C 3 N 4 nanosheets and in situ growth of Au NPs. The prepared heterostructures exhibited a universal catalytic ability toward organic dyes, such as methylene blue (MB), rhodamine 6G, and Congo red, in the presence of sodium borohydride (NaBH 4 ). The catalytic activity would improve under high SMt/g-C 3 N 4 /Au NPs concentration, high temperature, and high pH values. For example, the apparent reduction rate constant (k app ) and turnover frequency (TOF) toward MB can reach 5.91 min −1 and 302 h −1 , respectively, at 35 °C and pH values of 11. Furthermore, the influences of the pH values on the catalytic performance were investigated, and the reason can be attributed to the strong enhanced adsorption capacity of SMt/g-C 3 N 4 /Au NPs heterostructures toward organic dyes under the high pH values for facilitating electron transfer from NaBH 4 to organic dyes. Moreover, the SMt/g-C 3 N 4 /Au NPs heterostructures were quite stable, being recycled at least 10 times with almost unchanged k app . The excellent catalytic performance and recyclability recommend our synthesized SMt/g-C 3 N 4 /Au NPs heterostructures for a wide range of applications in environment and wastewater treatment.

Tubular CoFeP@CN as a Mott–Schottky Catalyst with Multiple Adsorption Sites for Robust Lithium−Sulfur Batteries

“…[20][21][22] In terms of geometric structure, graphite C 3 N 4 nanosheets (s-CN) prepared by the traditional liquid-phase exfoliation method usually suffer from low SSA due to re-aggregation by van der Waals forces. [23] On the other hand, template methods to produce high-SSA C 3 N 4 are cumbersome and wasteful, inappropriate for a technology with a huge potential market and thus potentially requiring enormous amounts of materials. [19] Besides, the catalytic activity of C 3 N 4 -based catalysts can be significantly augmented by altering their electronic structures through tuning the surface/interface atom environment.…”

Towards mass production of a spherical montmorillonite@covalent organic framework@gold nanoparticles heterostructure as a high-efficiency catalyst for reduction of methylene blue

“…S6, the R MB increased from 13.0% to 25.4% as the increase of pH values from 4 to 11. Hence, pHzpc was detected to prove the relationship between the adsorption and pH values (Zhang et al, 2020b). As shown in Fig.…”

Towards application of a covalent organic framework-silver nanoparticles@sand heterostructure as a high-efficiency catalyst for flow-through reduction of organic pollutants

“…S12). The good stability of the catalyst could be contributed to the strong adhesion of polydopamine [31]. Besides, the large-sized sand can effectively prevent the release of catalysts on the filtrate.…”