Development of a Stable MnCo₂O₄ Cocatalyst for Photocatalytic CO₂ Reduction with Visible Light

The synthesis of uniform MnCo₂O₄ microspheres and their cooperation with a visible light harvester to achieve efficient photocatalytic CO₂ reduction under ambient conditions are reported here. The MnCo₂O₄ materials were prepared by a facile two-step solvothermal-calcination method and were characterized by XRD, SEM, TEM, EDX, XPS, elemental mapping, and N₂ adsorption measurements. By using the MnCo₂O₄ microspheres as a heterogeneous cocatalyst, the photocatalytic performance of the CO₂-to-CO conversion catalysis was remarkably enhanced, and no decrease in the promotional effect of the cocatalyst was observed after repeatedly operating the reaction for six cycles. ¹³CO₂ isotope tracer experiments verified that the CO product originated from the CO₂ reactant. The effect of synthetic conditions and various reaction parameters on the photocatalytic activity of the system were investigated and optimized. The stability of the MnCo₂O₄ cocatalyst in the CO₂ reduction system was confirmed by several techniques. Moreover, a possible mechanism for MnCo₂O₄-cocatalyzed CO₂ photoreduction catalysis is proposed

Supplementary document for The Origination of Chiroptical Effect in Plasmonic Nano-Structures in the View of Quasi-Normal Mode Theory - 6832026.pdf

Supplemental informatio

Hydroxyl-Bonded Ru on Metallic TiN Surface Catalyzing CO₂ Reduction with H₂O by Infrared Light

Synchronized conversion of CO2 and H2O into hydrocarbons and oxygen via infrared-ignited photocatalysis remains a challenge. Herein, the hydroxyl-coordinated single-site Ru is anchored precisely on the metallic TiN surface by a NaBH4/NaOH reforming method to construct an infrared-responsive HO-Ru/TiN photocatalyst. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (ac-HAADF-STEM) and X-ray absorption spectroscopy (XAS) confirm the atomic distribution of the Ru species. XAS and density functional theory (DFT) calculations unveil the formation of surface HO-RuN5–Ti Lewis pair sites, which achieves efficient CO2 polarization/activation via dual coordination with the C and O atoms of CO2 on HO-Ru/TiN. Also, implanting the Ru species on the TiN surface powerfully boosts the separation and transfer of photoinduced charges. Under infrared irradiation, the HO-Ru/TiN catalyst shows a superior CO2-to-CO transformation activity coupled with H2O oxidation to release O2, and the CO2 reduction rate can further be promoted by about 3-fold under simulated sunlight. With the key reaction intermediates determined by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and predicted by DFT simulations, a possible photoredox mechanism of the CO2 reduction system is proposed

Chiral Plasmonic Shells: High-Performance Metamaterials for Sensitive Chiral Biomolecule Detection

Low-cost and large-area chiral metamaterials (CMs) are highly desirable for practical applications in chiral biosensors, nanophotonic chiral emitters, and beyond. A promising fabrication method takes advantage of self-assembled colloidal particles, onto which metal patches with defined orientation are created using glancing angle deposition (GLAD). However, using this method to make uniform and well-defined CMs over macroscopic areas is challenging. Here, we fabricate a uniform large-area colloidal particle array by interface-mediated self-assembly and precisely control the structural handedness of chiral plasmonic shells (CPSs) using GLAD. Strong chiroptical signals arise from twisted currents at the main, corner, and edge of CPSs, allowing a balance between strong chiroptical and high transmittance properties. Our shell-like chiral geometry shows excellent sensor performance in detecting chiral molecules due to the formation of uniform superchiral fields. Systematic investigations optimize the interplay between peak and null point resonances in different CPSs and result in a record consistency chiral sensor parameter U, i.e., 3.77 for null points and 0.0867 for peaks, which are about 54 and 1.257 times larger than the highest value (0.068) of previously reported CMs. The geometrical chirality, surface plasmonic resonance, chiral surface lattice resonance, and chiral sensor performance evidence the chiroptical effect and the excellent chiral sensor performance