• Energy Research

AbstractGold, silver, platinum and palladium typically crystallize with the face-centred cubic structure. Here we report the high-yield solution synthesis of gold nanoribbons in the 4H hexagonal polytype, a previously unreported metastable phase of gold. These gold nanoribbons undergo a phase transition from the original 4H hexagonal to face-centred cubic structure on ligand exchange under ambient conditions. Using monochromated electron energy-loss spectroscopy, the strong infrared plasmon absorption of single 4H gold nanoribbons is observed. Furthermore, the 4H hexagonal phases of silver, palladium and platinum can be readily stabilized through direct epitaxial growth of these metals on the 4H gold nanoribbon surface. Our findings may open up new strategies for the crystal phase-controlled synthesis of advanced noble metal nanomaterials.

202310 bcvc ; Version of Record ; RGC ; Others ; Shenzhen Science and Technology Program; National Natural Science Foundation of China; ITC via Hong Kong Branch of National Precious Metals Material Engineering Research Center (NPMM); funding for the Projects of Strategic Importance of The Hong Kong Polytechnic University; City University of Hong Kong ; and by the Departmental General Research Fund (project code: ZVUL) from the Department of Applied Biology and Chemical Technology of the Hong Kong Polytechnic University ; Published ; CC

Efficient, low-cost polymer/nanocrystal (NC) hybrid solar cells fabricated from aqueous materials, a PPV precursor and CdTe NCs, were demonstrated. The cells showed an efficiency of 2.14% under AM 1.5 (100 mW cm−2). This work provided a facile and feasible protocol to produce efficient solar cellsvia a cheaper and greener route.

Hierarchical TiC hollow branched fibres are synthesized and demonstrate high-rate supercapacitor energy storage with remarkable wide-temperature specific capacitance and excellent cycling stability.

While SnO2 is regarded as a good material for Li ion storage because of its high theoretical capacity, its microstructured powder form cannot be directly used as battery electrode because of a drastic pulverization problem and thus poor cyclic performance. Nanostructuring offers opportunities to circumvent this drawback. We report the construction of SnO2 nanoflake branches onto robust TiO2 nanotube stems. This core-branch nanostructured electrode demonstrate evidently improved Li ion storage properties compared to powders, with more stable cycling processes and higher rate capability. In this design, the TiO2 nanotube stems are realized by atomic layer deposition and offer a low-mass scaffold for the SnO2 nanoflakes and also a charge conductive path.

Uniform carbon fibers evolved from bamboo chopsticks garbage are achieved by a facile hydrothermal method, exhibiting competitive electrochemical behavior with commercial graphite, or pretty high anodic performance after being optimized.

Poly(1,4-naphthalenevinylene), prepared from a water-soluble precursor, was used to fabricate hybrid solar cells by blending with water-soluble CdTe nanocrystals (NCs) to act as the photoactive layer. In composites with CdTe NCs as the electron acceptors in a bulk heterojunction configuration, the devices exhibited a short-circuit current density of -6.14 mA/cm(2), an open-circuit voltage of 0.44 V, a fill factor of 0.32, and a power conversion efficiency of 0.86% under AM1.5G conditions. Because the devices were fabricated from water-soluble materials, the procedure was generally simple and environmentally friendly in comparison to the conventional devices fabricated from oil-soluble materials.