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Polymeric carbon nitride (CN) as a metal-free photocatalyst with suitable band gap has attracted increasing attention. However, pristine CN has a limited visible-light absorption range and also suffers a high recombination rate of photo-excited charge carriers, resulting in low photocatalytic activity. With the development of modern material characterization technology and electronic structure calculation technology, it is found that vacancy defects in CN play a more decisive role in determining the kinetics, energetics and mechanism of photocatalytic reactions. Therefore, much effort has been made in the past years to enhance the visible light activity of CN through defects control. This review provides the recent progresses and technologies on fabricating defective CN, in which the bottom-up and top-down preparation strategies are systematically summarized. In the meantime, the advancement of defective CN photocatalysts toward versatile applications such as water oxidation, hydrogen production, CO2 reduction, nitrogen fixation, H2O2 and organic synthesis, and pollutants removal are fully discussed. Finally, the existing opportunities and challenges of CN photocatalysts designed with vacancies defects are proposed to highlight the development direction of this field. This paper can lay a theoretical basis and guidance for the preparation of defective graphitic carbon nitride.

Graphitic carbon nitride (g-C3N4), as a significant metal-free photocatalyst, has elicited ripples of excitement due to its many extraordinary features, such as its mild bandgap, high thermal and chemical stability, inexpansive, and environmental friendly. However, the unsatisfactory solar light absorption, low surface area and the rapid recombination of photogenerated charges severely restrict the photocatalytic activity of bulk g-C3N4. Especially, g-C3N4 with a bandgap of 2.7 eV means an absorption threshold at about 450 nm that is still insufficient for efficient visible light capturing and leaves the near-infrared (NIR) light spectrum unexploited. In order to facilitate future material design for efficient g-C3N4 photocatalysts under solar light (UV ~5%, visible light ~43%, NIR light ~52%), we reviewed the recent progress of NIR-driven g-C3N4 based photocatalysts. Many strategies, including combination of narrow optical gap materials, bandgap engineering, upconversion materials, plasmonic materials, and photosensitizers, have been summarized to broaden the light absorption of g-C3N4 to NIR light region. Besides, the diverse photocatalytic applications of NIR driven g-C3N4 photocatalysts have been summarized, including water purification, water splitting, N2 photofixation, CO2 reduction, NO removal, H2O2 production, bacteria disinfection, photodynamic therapy and organic synthesis, etc. The mechanism and the roles of various strategies in the NIR photocatalytic process were highlighted in details. Moreover, the limitations and possible solutions for each method are discussed.

Caspases, a family of cysteine proteases, comprise of highly homologous enzymes that play an important role in apoptotic cell death. Caspase-3 shows key functions in apoptosis, mediating apoptotic cascade from the intrinsic and extrinsic activation pathways. Therefore, caspase-3 is an attractive target for therapeutic intervention. For instance, inhibitors of caspase-3 have been described as promising cardioprotectants, neuroprotectants and antiarthritic agents. A novel peptidomimetic inhibitor of caspase-3, has been designed, which still has the properties of a reversible inhibitor, while the PI site at the C-terminal remains, and only L -amino acid has been replaced by D -amino acid. Also presented here is the synthesis of the inhibitor and its inhibitory activity against caspase-3, which was tested by the fluorescent activity assay.

A new polyborate containing chiral metal-complex Zn (en)3 B5 O7 (OH)3, where en = ethylenediamine, was synthesizedunder solvothermal conditions and structurally characterized by means of X-ray diffraction analysis. Crystal data: Zn(en)3 B5 O7 (OH)3, monoclinic, space group P21/c, a = 0.8532(72) nm, b = 2.3340(5) nm, c = 0.9526(92) nm, β = 107.04(3)°, Z = 4, V = 1.8140(6) nm3, Dc = 1.694 g/cm3, μ = 1.416 mm−1, F(000) = 960, GOF = 1.020, R =0.0276, Rw = 0.0828. There is a chiral Zn(en)2+3 complex cation and an isolated B5O7 · (OH)2−3 group in a Zn(en)3B5O7(OH)3 molecule. The enantiomer of the chiral complex cation is separated orderly as Δ and Λ configurations in the compound and the borate group consists of two B3O3 cycles linked through a bridging boron atom.