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• Cu/Cr bilayer films were deposited onto diamond to simulate actual interface in Cu/diamond composites. • The h between Cu and diamond was measured by a time-domain thermoreflectance technique. • The Cu/Cr/Cr 3 C 2 /diamond structure with a mixed Cr and Cr 3 C 2 interlayer exhibits the maximum h value of 168 MW/m2 K. • This study provides guideline for interface modification to attain high thermal conductivity in Cu/diamond composites. Interfacial thermal conductance (h) plays a decisive role in attaining high thermal conductivity in diamond particles reinforced Cu matrix (Cu/diamond) composites for promising thermal management applications. In this article, Cu/Cr bilayer films were deposited onto a single-crystalline diamond substrate by magnetron sputtering to form a Cu/Cr/diamond sandwich structure to clarify the role of the Cr interlayer in determining h between Cu and diamond. The 50 nm-thick Cr film was deposited at 773 K with various lengths of holding time to regulate the transformation of Cr to Cr 3 C 2. The h between Cu and diamond was experimentally measured by a time-domain thermoreflectance technique. The Cu/Cr/Cr 3 C 2 /diamond structure with a mixed Cr and Cr 3 C 2 interlayer exhibits an h value of 168 MW/m2 K, higher than 57 MW/m2 K for the Cu/diamond structure, 96 MW/m2 K for the Cu/Cr/diamond structure, and 86 MW/m2 K for the Cu/Cr 3 C 2 /diamond structure. The Cr interlayer improves the interfacial bonding and reduces the acoustic impedance mismatch between Cu and diamond; however, the full transformation of Cr to Cr 3 C 2 reduces the h value due to lower thermal conductivity of Cr 3 C 2 than Cr. This study provides guideline for interface modification to attain high thermal conductivity in Cu/diamond composites. [ABSTRACT FROM AUTHOR]

BiVO 4 film coupled with resorcinol–formaldehyde resin (RFS) nanoparticles to form BiVO 4 /RFS heterojunction film as photoanode for solar water oxidation. The conduction and valence band potential of RFS nanoparticles were lower than those of BiVO 4 , and the surface holes and electrons could be directionally transferred to RFS nanoparticles and BiVO4 film, respectively. [Display omitted] • BiVO 4 /RFS film photoanodes were prepared by coupling BiVO 4 films with resorcinol–formaldehyde resin nanoparticles for solar water oxidation. • The light harvesting and electrochemical properties of the optimal BiVO 4 /RFS film was close to the BiVO 4 film. • Better water oxidation activity, kinetics and stability were observed on the BiVO 4 /RFS film photoanode. • The conduction and valence band potential of RFS nanoparticles were lower than those of BiVO 4 , and their surface holes and electrons could be directionally transferred to RFS nanoparticles and BiVO 4 film, respectively. The poor properties of carrier separation and transfer on BiVO 4 surface are two major bottlenecks for nanostructured BiVO 4 photoanodes during solar water oxidation. Herein, BiVO 4 /resorcinol–formaldehyde resin (BiVO 4 /RFS) heterojunction films were prepared by coupling resorcinol–formaldehyde resin (RFS) nanoparticles on BiVO 4 films' surface, and investigated as photoanodes for solar water oxidation. The light harvesting and electrochemical properties of the resultant BiVO 4 /RFS film was close to the BiVO 4 film, but its carrier radiative recombination was weakened significantly. Relative to the BiVO 4 film photoanode, better water oxidation activity, kinetics and stability were observed on the BiVO 4 /RFS film photoanode. The conduction and valence band potential of RFS nanoparticles were discovered to be lower than those of BiVO 4 , and the surface photogenerated holes and electrons could be directionally transferred to RFS nanoparticles and BiVO 4 film, respectively. The higher solar water oxidation performance on the BiVO 4 /RFS photoanode was mainly originated from the separation and transfer of surface carrier through the BiVO 4 /RFS coupling interfaces under AM 1.5G irradiation. The present work could provide inspiration in the design and development of similar heterojunction materials for solar water splitting. [ABSTRACT FROM AUTHOR]

Abstract: ZnO quantum-dot chains codoped with Eu3+ and Er3+ were synthesized by the chemical precipitation method and the codoping effects on the structures, morphologies and optical properties of the powders were briefly investigated. The X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) results indicated the Eu3+ and Er3+ were incorporated into the crystal lattice of ZnO host. Transmission electron microscope (TEM) measurements showed the sizes of the ZnO quantum dots decreased with the increase of Eu3+ and Er3+ doping concentration, and the quantum-dot chains were formed by codoping with Eu3+ and Er3+. The green emissions in the photoluminescence spectra were attributed to 4f–4f of Er3+ inner shell 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions, and the characteristic red emissions of Eu3+ ions were attributed to the 5D0 → 7F1 and 5D0 → 7F2 transitions, respectively. Moreover, the red emission of the Eu3+ ions gradually decreased with the Er3+ ions doping concentration increased, which may be due to the different energy storage centers in the powders. [Copyright &y& Elsevier]