Engineering oxygen-containing and amino groups into two-dimensional atomically-thin porous polymeric carbon nitrogen for enhanced photocatalytic hydrogen production

Abstract

Oxygen-containing and amino groups functionalized polymeric carbon nitride atomically-thin porous nanosheets with hydrophilic surfaces and strong Lewis basicity are designed and synthesized for enhanced photocatalytic H2evolution.

Synthesis of g‐C3N4 Nanosheets by Using a Highly Condensed Lamellar Crystalline Melamine–Cyanuric Acid Supramolecular Complex for Enhanced Solar Hydrogen Generation

“…The XRD pattern of the CN‐AA sample obtained after the calcination of CN‐A in air (Figure ) showed a slight shift of the 0 0 2 peak (2 θ =26.9°) with a small decrease in the interlayer distance ( d =0.332 nm). This phenomenon is possibly attributable to the introduction of functional groups (e.g., C=O) on nanosheets during the calcination, which increases the interaction between nanosheets …”

“…Notably, this increase of C=O groups is consistent with XRD analysis, revealing its role in the crystalline structure of CN‐AA. As electronegativity of oxygen (3.44) is higher than that of nitrogen (3.04), the interaction between the nanosheets become stronger . Therefore, the distance between the nanosheets of CN‐AA is decreased compared to CN‐A.…”

“…Recently, Meng et al. reported the synthesis of thin‐porous carbon nitride nanosheets with high photocatalytic activity under full sunlight . However, the photoactivity was reduced approximately 6.6 times upon switching to visible light.…”

“…This phenomenon is possibly attributable to the introductiono ff unctional groups (e.g.,C =O) on nanosheets during the calcination, which increasest he interaction between nanosheets. [21] The 001p eak disappeared in the XRD pattern of CN-AA,i mplying ab reakageo fh ydrogen bonds in the intralayer framework duringt he additional calcination step. [22] To understand the polycondensation of CN under Ar treatment,t he effect of heatingt ime wass tudied.…”

Carbon Dots–Implanted Graphitic Carbon Nitride Nanosheets for Photocatalysis: Simultaneously Manipulating Carrier Transport in Inter‐ and Intralayers

“…These shortcomings severely limit its development in the field of photocatalysis. To address these issues, various studies have focused on the synthesis of ultrathin 2D nanosheets by using fluorination followed by thermal defluorination, liquid phase exfoliation, alkaline activation with thermal exfoliation, self‐modification through successive thermal treatment, Zn‐assisted thermal treatment, and salt‐mediated synthesis . The apparent advantages of such kinds of 2D nanosheets include short diffusion length from the bulk to the interface to reduce the transfer resistance, low recombination probability of photogenerated carriers, and enlarged specific surface areas providing abundant reactive sites .…”