Various colors of photoluminescent SiC-dots/SiO2 prepared through a simple heating process have been employed for optical and electrochemical applications. Blue (B)-, green (G)-, and tan (T)-SiC-dots/SiO2 powders have been prepared from SiC-dots that had been prepared from 3-aminopropyl trimethoxysilane through a hydrothermal route by simply controlling heating at 60 °C for 60 min and 300 °C for 10 and 20 min, respectively. The B-, G-, and T-SiC-dots/SiO2 nanocomposites emit at 455, 534, and 574 nm, respectively, under excitation at 360 nm. B-, G-, and T-SiC-dots/SiO2 glass films show at least seven colors when excited at 360, 460, and 520 nm. Through a heat-induced photoluminescence (PL) change, a representative lithographic pattern of B-SiC-dots/SiO2 films has been fabricated using a near-infrared laser. The B-, G-, and T-SiC-dots/SiO2 also possess high electrocatalytic activity for the oxygen reduction reaction. Having such interesting PL and electrical properties, the stable, low-toxic, and cost-effective B-, G-, and T-SiC-dots/SiO2 nanocomposites show great economic potential in many applications such as light-emitting diodes, photoluminescent windows, and fuel cells.

A facile and one-pot approach to the preparation of gold (Au) and copper (Cu) bimetallic nanoclusters (NCs) is unveiled. AuCu NCs reveal features of orange photoluminescence (PL), reversible pH-dependent PL properties, and efficient catalytic activity for degradation of methylene blue (MB).

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We have synthesized Cu 9 S 8 /carbon nanotube (CNT) nanocomposites (NCs) with high electrocatalytic activity for direct methanol fuel cells (DMFCs). Cu 9 S 8 /CNT NCs are prepared from Cu(NO 3 ) 2 , CNTs, and thioacetamide in the presence of poly(vinylpyrrolidone) under alkaline conditions. There are Cu 9 S 8 nanoparticles (diameter: 50 AE 6 nm) and aggregates on the surfaces of CNTs. The as-prepared Cu 9 S 8 / CNT NC modified electrodes provide a four-electron pathway for the oxygen reduction reaction (ORR) in alkaline media. Three representative Cu 9 S 8 /CNT electrodes (mass loading: 1.63 mg cm À2 ) provide a mean limiting current density of 3.43 AE 0.03 mA cm À2 (each with three measurements) at a constant scan rate of 1 mV s À1 and a rotation rate of 3600 rpm. At a constant potential of À0.5 V, the kinetic rate constant for the Cu 9 S 8 /CNT is 2.82 Â 10 À2 cm s À1 , revealing higher activity of the Cu 9 S 8 /CNT electrodes in the ORR. The Cu 9 S 8 /CNT relative to Pt/C electrodes is more tolerant against methanol and carbon monoxide poisoning. These low-cost, stable, and highly active Cu 9 S 8 /CNT electrodes have great potential for use in DMFCs.

A facile and one-pot wet chemical approach has been applied for the preparation of palladium copper (PdCu) nanosponges (NSs) through the reduction of Pd 2+ and Cu 2+ ions with L-ascorbic acid in the presence of sodium dodecyl sulfate (SDS) at 95 °C. The PdCu NSs prepared in the presence of 12.5, 25, and 37.5 mM SDS have sizes of 46.0 ± 4.3, 36.8 ± 4.5, and 37.2 ± 2.6 nm, respectively. Relative to a Pd NPs electrode (0.33 mA cm −2 ), Cu NPs electrode (0.31 mA cm −2 ), commercial Pd/C electrode (0.34 mA 10 cm −2 ) and Pt/C electrode (0.66 mA cm −2 ), PdCu NS-modified electrodes provide high current density for oxygen reduction reaction (1.93 mA cm −2 ) under alkaline conditions. In addition, the PdCu NS-modified electrodes provide high catalytic activity for glucose oxidation at −0.01 V vs. Ag/AgCl and are stable even after sweeping for 43200 s in 0.1 M NaOH containing 0.1 M glucose. The higher catalytic activity of the PdCu NSs is mainly due to their greater electroactive surface area (EASA) and synergistic effect 15 caused by the intimate contact between Pd and Cu. The PdCu NS-modified electrodes exhibit high sensitivity (1560 µA mM −1 cm −2 ), good selectivity, and fast response to glucose over a linear range of 0−30 µM (R 2 = 0.997), with a limit of detection (LOD) of 4.1 µM. Having the advantages of good stability, excellent electrocatalytic activity, and cost effectiveness, the PdCu NSs hold great potential for use in fuel cells using methanol or ethanol as fuel and for the fabrication of electrochemical sensor for the 20 detection of glucose in blood samples.