The type-II CdO/CdS heterostructure is a promising visible light water-splitting photocatalyst.

Single-layered graphene quantum dots with dual recognition sites including π-conjugated single sheets and positively charged sites were developed and used for monitoring the mitochondrial ATP fluctuation in living cells.

By means of a hybrid density functional, we comprehensively investigate the energetic, electronic, optical properties, and band edge alignments of two-dimensional (2D) CdS/g-C ${}_3$ N ${}_4$ heterostructures by considering the effect of biaxial strain and pH value, so as to improve the photocatalytic activity. The results reveal that a CdS monolayer weakly contacts with g-C ${}_3$ N ${}_4$ , forming a type II van der Waals (vdW) heterostructure. The narrow bandgap makes CdS/g-C ${}_3$ N ${}_4$ suitable for absorbing visible light and the induced built-in electric field between the interface promotes the effective separation of photogenerated carriers. Through applying the biaxial strain, the interface adhesion energy, bandgap, and band edge positions, in contrast with water, redox levels of CdS/g-C ${}_3$ N ${}_4$ can be obviously adjusted. Especially, the pH of electrolyte also significantly influences the photocatalytic performance of CdS/g-C ${}_3$ N ${}_4$ . When pH is smaller than 6.5, the band edge alignments of CdS/g-C ${}_3$ N ${}_4$ are thermodynamically beneficial for oxygen and hydrogen generation. Our findings offer a theoretical basis to develop g-C ${}_3$ N ${}_4$ -based water-splitting photocatalysts.

Recently, the application of novel nanomaterials, especially magnetic nanomaterials in the development of latent fingerprints (LFP), has become the hot focus for forensic scientists and criminal investigators. As a type of recyclable, environment-friendly material, Fe₃O₄ nanoparticles achieve a wonderful effect in visualization of LFP. We first report the synthesis and encapsulation of nano-Fe₃O₄ through “facile coprecipitation”, (3-mercaptopropyl)triethoxysilane was covalently embedded into Fe₃O₄ nanoparticles, and the Fe₃O₄ core was encapsulated by the nanosilver to prepare novel magnetic nanomaterials ([email protected]) with the core–shell configuration. For comparison, the magnetic nanomaterials ([email protected]) were prepared by surface modification. Their composition, structure, and properties were characterized by SEM, TEM, XRD, IR, XPS, and VSM. Compared with commercially available gold powder, silver powder, bare magnetic powder, and prepared [email protected], the development effect of LFP on different objects by using [email protected] had better performance, which presented the advantages of low background interference, high sensitivity, and clear secondary details in LFP. In the crime scenes of some influential cases, [email protected] had been applied to the visualization of LFP. The biometric identification of criminal suspects was confirmed through fingerprint comparison, which was highly affirmed by the public security department.

The stimulus-responsive room-temperature phosphorescence (RTP) materials have become an increasingly significant topic in the fields of bioimaging, sensing, and anticounterfeiting. However, this kind of materials is scarce to date, especially for the ones with delicate stimulus-responsive behavior. Herein, a universal strategy for multilevel thermal erasure of RTP via chromatographic separation of host-guest doping RTP systems is proposed. The tunable host-guest systems, matrix materials, heating temperature, and time are demonstrated to allow precise six-level data encryption, QR code encryption, and thermochromic phosphorescence encryption. Mechanistic study reveals that the thermal-responsive property might be attributed to molecular thermal motion and the separation effect of the silica gel, which provides expanded applications of host-guest RTP materials such as cold chain break detection. This work offers a simple yet universal way to construct advanced responsive RTP materials.

A computational study using the B3LYP density functional was carried out to explore the effects of counterions and solvents on the Au(I)-catalyzed cyclization reaction of indole-allenoate to form dihydrocyclopenta[b]indole derivatives. The optimal reaction path includes intramolecular cyclization and proton transfer steps. In the first process, the counterions Cl⁻, BF₄ ⁻ and OTf⁻ act as hydrogen-bond acceptors to promote the intramolecular cyclization between the C1 and C5 atoms. In the proton transfer step, the anions greatly reduce the energy barrier of proton migration, in the form of a proton-transfer shuttle. More importantly, the Bronsted/Lewis basicity of the counterions (Cl⁻ > OTf⁻ > BF₄ ⁻) turns out to be the primary reason for the difference in the counterion catalytic activity in the proton-transfer process. During the protonation of the counterion, the catalytic capacities of the counterions show significant differences according to the series Cl⁻ > OTf⁻ > BF₄ ⁻, and the order of the catalytic ability of the counterions was found to be Cl⁻ < OTf⁻ < BF₄ ⁻ in the deprotonation of the counterion-H. Interestingly, the strong coordinating capability of the solvents (DMF and DMSO vs. PhCH₃) was found to be another important factor that critically affects the reaction yield (0%, 0% and 95% yield, respectively). Overall, our calculations not only explain the experimental phenomena well, but also put forward some guidance and advice for the selection of counterions and solvents for transition metal-catalyzed reactions, including proton-transfer processes.