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Two-dimensional graphitic carbon nitrides (2D g-C3N4) are promising photocatalysts for water splitting to hydrogen due to their non-toxicity and high stability. However, the bulk g-C3N4 has some intrinsic drawbacks, such as rapid electron–hole recombination and low charge-carrier mobility, resulting in poor photocatalytic activity. Here, 2,4-diamine-6-phenyl-1,3,5-triazine was employed as a precursor to regulating the assembly of melamine and cyanuric acid in water. The resulting g-C3N4 not only improved the visible light absorption and electron–hole separation but also provided more catalytic sites for enhanced photocatalytic hydrogen evolution. The modified g-C3N4 (CNP10-H) showed a hydrogen-releasing rate of 2184 μmol·g−1·h−1, much higher than the bulk g-C3N4. [ABSTRACT FROM AUTHOR]

This research reported electro-static junctions between carbon nanotubes (CNT) and graphitic carbon nitride (CCN) with enhanced photocatalytic properties. The CNT and CCN formed the CTCN (CNT/CCN) by the electro-statistic driving force under hydrothermal methodology. The materials fabrication was confirmed by using different analyzing techniques such as SEM, TEM, XRD, and FTIR (etc). Also, the photocatalytic ability was studied by the degradation of R-610 under visible light irradiation. The CTCN-1 possess the higher degradation rate 0.0105 min−1 and higher current density 0.19 μA/cm2 as compare to other, CTCN-2 (0.0088 min−1, 0.16 μ A/cm2), CTCN-3 (0.0065 min−1, 0.12 μ A/cm2) and CCN (0.0035 min−1, 0.10 μ A/cm2). The combining of CNT with CCN in a specific amount reduces the structure defects in graphitic carbon nitride by reducing the charge recombination ability. Ion-trapping experiments showed that superoxide radicals and holes are the most generated and effective photogenerated species to accomplish the degradation of R-610 (rhodamine-610) under visible light irradiation. • Electro-statistic junctions between CNT and graphitic carbon nitride was created. • Optimum quantity of CNT with CCN can reduce the structure defects. • O− 2 and h+ are the most effective photogenerated species to accomplish the R-610. [ABSTRACT FROM AUTHOR]

This study focused on the fabrication of a peculiar 3D/2D ZnIn 2 S 4 /oxygen-doped graphitic carbon nitride (ZnIn 2 S 4 /SO-GCN) through a simple hydrothermal method. The flower-like morphology of hexagonal ZnIn 2 S 4 disperse on the SO-GCN nanosheets are evidenced by XRD, scanning and transmission electron microscopy. The as-synthesized nanocomposites were intensively applied for the visible light photocatalytic removal of aqueous phase 2,4-D. The heterojunction creation and the well-developed combined interface between ZnIn 2 S 4 and SO-GCN significantly increases its photogenerated charge separation capability. The photo-degradation mechanism disclose that the heterojunction has improved catalytic degradation activity, due to efficient transferring of photogenerated electron-holes pairs. Under visible-light irradiation, these nanocomposites showed 3–5 times higher degradation rate of 2,4-D (i.e. 0.0112/min, by 30%-ZnIn 2 S 4 /SO-GCN), as compared to solo ZnIn 2 S 4 and SO-GCN, attributed to the composite's synergistic effect in unique 3D/2D heterojunction, that accelerates the electron-hole separation. The h+ and •OH species contribute a noteworthy role in the degradation process of 2,4-D over 30%-ZnIn 2 S 4 /SO-GCN. In addition, the synthesized nanocomposites sustained their reusability performance in five cyclic run. Our research have implications of constructing 3D/2D nanocomposites which is beneficial for scalable solution of efficient photocatalysts. • Flower like ZnIn 2 S 4 /SO-GCN heterojunction was synthesized by hydrothermal method. • Interfacial microstructures significantly enhanced the photocatalytic performance. • A typical Type II heterostructure was confirmed between SO-GCN and ZnIn 2 S 4. • The degradation rate of 2,4-D by 30%-ZnIn 2 S 4 /SO-GCN was investigated. [ABSTRACT FROM AUTHOR]

A novel and highly efficient ternary mpg-C 3 N 4 /BiVO 4 /TiO 2 composite was successfully synthesized and characterized with regard to structure, chemical composition, optical properties and degradation application. The photocatalytic activities of as-prepared samples were evaluated by the photocatalytic decomposition of methylene blue (MB), practical effluent from alkylation and amination steps in 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) production. Compared with TiO 2 , BiVO 4, and mpg-C 3 N 4 , the binary composites TiO 2 /BiVO 4 and the ternary mpg-C 3 N 4 /BiVO 4 /TiO 2 composites exhibited the higher photocatalytic activity under visible light irradiation. Compared to solo mpg-C 3 N 4 and BiVO 4 , the photocatalytic efficiency of g-C 3 N 4 /TiO 2 /BiVO 4 raised up to 94%. The catalytic activity of g-C 3 N 4 /TiO 2 /BiVO 4 against TATB (alkylation and amination) also confirms its efficiency by creating intermediate which were detected by Q-TOF-MS. The thermal stability and photo-stability of the produced composites were investigated. From the view of practical application, mpg-C 3 N 4 /BiVO 4 /TiO 2 displayed superior photostability after five times recycle. The mechanism research showed the fitting of band structure among BiVO 4 , g-C 3 N 4, and TiO 2 . The presence of mpg-C 3 N 4 and BiVO 4 can notably adjust the band gap energy and the synergy effects of them can prolong the lifetime of the charge carrier. [ABSTRACT FROM AUTHOR]