Mechanochemical Synthesis of Nitrogen-Deficient Mesopore-Rich Polymeric Carbon Nitride with Highly Enhanced Photocatalytic Performance

Abstract

Creation of defects and mesopores in polymeric carbon nitride (CN), a promising photocatalyst for practical applications, is highly effective in enhancing the photocatalytic performance; however, environmentally friendly physical methods (e.g., mechanical ball-milling) and effective means for the simultaneous formation of defects and mesopores in CN to synergistically enhance the photoactivity are still scarce. Herein, a mechanochemical method was successfully used to synthesize mesopore-rich CN with nitrogen vacancies (mCNv) by mechanical ball-milling of the intermediate (melem) with succedent calcination. The simultaneous formation of nitrogen vacancies and mesopores in mCNv arises from the ball-milling-induced structure distortion and morphological variation of the intermediate with massive rupture of intermolecular hydrogen bonds. The as-prepared mCNv exhibits enlarged specific surface area, considerably thinned nanosheets, extended visible light absorption, enhanced photoexcited charge separation and transfer, and thus ∼6.3-fold improved photocatalytic H 2 evolution activity under visible light irradiation, compared with the bulk CN. This work provides a novel, universal, and industrializable technique for simultaneous creation of defects and mesopores in CN.

Promoting Spatial Charge Transfer of ZrO2 Nanoparticles: Embedded on Layered MoS2/g-C3N4 Nanocomposites for Visible-Light-Induced Photocatalytic Removal of Tetracycline

“…In the presence of ZrO 2 @g-C 3 N 4 and MoS 2 / g-C 3 N 4 , the emission peak of the mixture is slightly lowered as a result of poor interactions between the constituents in the mechanical mix. 46 The EIS Nyquist plot provides an additional context for exploring spatial charge-transfer assets. The lower the charge-transfer resistance in the broad spectrum, the smaller the semicircle diameter of the EIS Nyquist plot as the spectrum narrows.…”

“…Figure a shows that, under 325 nm laser stimulation, pure g-C 3 N 4 exhibits an exceptionally bright photoluminescence pattern with the emission wavelength centered at about 460 nm, which can be attributed to its fast charge recombination. In the presence of ZrO 2 @g-C 3 N 4 and MoS 2 /g-C 3 N 4 , the emission peak of the mixture is slightly lowered as a result of poor interactions between the constituents in the mechanical mix . The EIS Nyquist plot provides an additional context for exploring spatial charge-transfer assets.…”

In situ formation of 2-thiobarbituric acid incorporated g-C3N4 for enhanced visible-light-driven photocatalytic performance

“… 35 The ultrathin nanosheet morphology and enriched nanoholes on the surface of TBA/CN-3 would provide more active sites and might lead to significant acceleration of the photo-excited charge separation and migration, subsequently resulting in much improved photoactivity. 36,37 …”

Copper loaded nitrogen-rich mesoporous carbon nitride as a highly efficient photocatalyst for selective oxidative cleavage of C(sp3)–C(sp3) bonds at room temperature under visible light

“…In comparison to traditional g-C 3 N 4 , nitrogen-rich mesoporous carbon nitride exhibits highly modied physicochemical properties, including a narrower band gap and electron-rich basicity, indicating its great promise towards various photocatalytic applications. [37][38][39][40][41][42][43] Moreover, as a result of the strong localized surface plasmon resonance (LSPR) effect, the combination of coinage metal nanoparticles and mpg-CN would further enhance the photocatalytic performance of mpg-CN, and meanwhile facilitates charge [hole(h + ) and electron(e À )] separation and effectively precludes h + /e À recombination in mpg-CN materials. 44 In our recent work, the Ag/C 3 N 4 nanometric semiconductor has proved to be a highly efficient photocatalyst for the single electron oxidation (SEO) of oxygen and nitrogen, and generated O-or Ncationic radicals as the initial species in certain reactions under visible light irradiation, respectively.…”

“…In comparison to traditional g-C 3 N 4 , nitrogen-rich mesoporous carbon nitride exhibits highly modified physicochemical properties, including a narrower band gap and electron-rich basicity, indicating its great promise towards various photocatalytic applications. 37–43…”