Seeded Growth of Au@CuxO Core-Shell Mesoporous Nanospheres and Their Photocatalytic Properties

Synthetic Approaches to Colloidal Nanocrystal Heterostructures Based on Metal and Metal-Oxide Materials

Composite inorganic nanoarchitectures, based on combinations of distinct materials, represent advanced solid-state constructs, where coexistence and synergistic interactions among nonhomologous optical, magnetic, chemical, and catalytic properties lay a basis for the engineering of enhanced or even unconventional functionalities. Such systems thus hold relevance for both theoretical and applied nanotechnology-based research in diverse areas, spanning optics, electronics, energy management, (photo)catalysis, biomedicine, and environmental remediation. Wet-chemical colloidal synthetic techniques have now been refined to the point of allowing the fabrication of solution free-standing and easily processable multicomponent nanocrystals with sophisticated modular heterostructure, built upon a programmed spatial distribution of the crystal phase, composition, and anchored surface moieties. Such last-generation breeds of nanocrystals are thus composed of nanoscale domains of different materials, assembled controllably into core/shell or heteromer-type configurations through bonding epitaxial heterojunctions. This review offers a critical overview of achievements made in the design and synthetic elaboration of colloidal nanocrystal heterostructures based on diverse associations of transition metals (with emphasis on plasmonic metals) and transition-metal oxides. Synthetic strategies, all leveraging on the basic seed-mediated approach, are described and discussed with reference to the most credited mechanisms underpinning regioselective heteroepitaxial deposition. The unique properties and advanced applications allowed by such brand-new nanomaterials are also mentioned.

Seeded Growth of Gold-Copper Janus Nanostructures as a Tandem Catalyst for Efficient Electroreduction of CO2 to C2+ Products

Gold-copper (Au-Cu) Janus nanostructures (Au-Cu Janus NSs) are successfully prepared using N-oleyl-1,3-propanediamine as capping agent and Cu(acac)₂ as the precursor in a typical seeded growth strategy. By preferably depositing Cu atoms on one side of concave cubic Au seeds, the Cu part gradually grows larger as more Cu precursors are added, making the size tuning feasible in the range of 74-156 nm. When employed as an electrocatalyst for electrochemical CO₂ reduction (CO₂ RR), the Au-Cu Janus NSs display superior performance to Au@Cu core-shell NSs and Cu NPs in terms of C₂₊ products selectivity (67%) and C₂₊ partial current density (-0.29 A cm^-2 ). Combined experimental verification and theoretical simulations reveal that CO spillover from Au sites to the nearby Cu counterparts would enhance CO coverage and thus promote C-C coupling, highlighting the unique structural advantages of the Au-Cu Janus NSs toward deep reduction of CO₂ . The current work provides a facile strategy to fabricate tandem catalyst with a Janus structure and validates its structural advantages toward CO₂ RR, which are of critical importance for the rational design of efficient CO₂ RR catalyst.

Confinement of nano-gold in 3D hierarchically structured gadolinium-doped ceria mesocrystal: synergistic effect of chemical composition and structural hierarchy in CO and propane oxidation

Gadolinium-doped ceria hierarchical gold catalyst shows four-fold TOF increase compared to undoped non-hierarchical system, proving the synergistic effect of doping and structural hierarchy in propane oxidation.

Photocatalytic Removal of Antibiotics on g-C3N4 Using Amorphous CuO as Cocatalysts

Amorphous CuO is considered as an excellent cocatalyst, owing to its large surface area and superior conductivity compared with its crystalline counterpart. The current work demonstrates a facile method to prepare amorphous CuO, which is grown on the surface of graphitic carbon nitride (g-C3N4) and is then applied for the photocatalytic degradation of tetracycline hydrochloride. The prepared CuO/g-C3N4 composite shows higher photocatalytic activities compared with bare g-C3N4. Efficient charge transfer between g-C3N4 and CuO is confirmed by the photocurrent response spectra and photoluminescence spectra. This work provides a facile approach to prepare low-cost composites for the photocatalytic degradation of antibiotics to safeguard the environment.