Search

Abstract: Red Gd2O3:Eu nanophosphors were prepared by novel sucrose-assisted combustion method. The sucrose hydrolysis and complexing procedures were discussed by the Fourier transform infrared spectroscopy (FTIR) analysis. The effect of sucrose-to-metal ratio (S:M) on morphology and luminescence intensity of Gd2O3:Eu nanocrystals were investigated. And the optimum ratio was found to be S:M=7:1, as confirmed by the results of scanning electron microscope (SEM), transmission electron microscope (TEM) and photoluminescence (PL) measurements. The highest photoluminescence emission from the particles obtained at S:M=7:1 was about 85% of the commercial red phosphors. [Copyright &y& Elsevier]

In this study, oxygen vacancies were introduced into the hematite (α-Fe 2 O 3) photoanode via a simple and rapid butane flame annealing method. The presence of oxygen vacancies were demonstrated by high-resolution transmission electron microscopy (HRTEM), electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS). The photocurrent density of optimum α-Fe 2 O 3 electrodes was 0.67 mA cm-2 at 1.23 V RHE , about 2.7 times higher than that of N 2 annealed electrode. Our study showed that butane flame annealing process can introduce oxygen vacancies defects in Fe 2 O 3 electrodes, which would improve carrier transfer efficiency, increase electron density, enhance water oxidation activity, and narrow the light optical bandgap. The use of butane flame annealing is a simple and effective strategy to enhance the PEC performance of hematite thin films. • Fe 2 O 3 photoanodes with oxygen vacancies were successfully synthesized through butane flame annealing. • Oxygen vacancies can improve charge transfer efficiency and increase the utilization rate of photogenerated holes at the interface. • The method of annealing with butane flame is simple and time-saving. • The FA-Fe 2 O 3 electrode achievs a light current density of 0.67 mA cm-2 at 1.23 V RHE. [ABSTRACT FROM AUTHOR]

Nanosized Ag 2 O decorated Bi 2 MoO 6 hierarchical microspheres were successfully prepared and evaluated as efficient visible-light-responsive photocatalysts. X-ray diffraction (XRD) patterns confirmed that the formation of the Ag 2 O and Bi 2 MoO 6 composites while scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDX) results revealed the relatively uniform deposition of Ag 2 O nanoparticles on the surface of Bi 2 MoO 6 microspheres. The visible light photocatalytic activity of the composites was studied by photodegradation of methyl orange (MO) and the composite with Ag to Bi ratio of 1: 1 shows the highest activity due to the effective separation of photocarriers. The photocatalytic mechanism study indicates photogenerated holes play a key role for the dye degradation. [ABSTRACT FROM AUTHOR]

Developing efficient and nonprecious electrocatalysts for oxygen evolution reaction (OER) is crucial for the hydrogen generation via water splitting. Here we report the direct growth of heterostructural Ni 2 P–Fe 2 P hybrid electrocatalysts on NiFe foams. The redox engineered NiFe foam (rNF) significantly enhances the OER performance. Among prepared catalysts, Ni 2 P–Fe 2 P/rNF performs the highest OER activity, driving the current densities of 10 and 100 mA cm−2 at low overpotentials of 218 and 270 mV in 1 M KOH, respectively. Meanwhile, it can maintain 100 mA cm−2 for 24 h without obvious degradation. The morphology and composition of NFP/rNF after OER test were carefully studied. This work suggests that self-supported bimetal phosphides of NFP/rNF is an efficient and durable electrode material for water oxidation. Heterostructural Ni2P-Fe2P hybrid electrocatalysts were direct grown on NiFe foams, which show excellent oxygen evolution activity and stability. Image 1 • The formation of micro-sized pores on the skeleton of NiFe foam (NF) substrate can enlarge surface area. • The heterogeneous Ni2P-Fe2P structure provides plentiful active sites for OER. • The Ni2P-Fe2P/ rNF foam exhibits an extraordinary electro catalytic performance. [ABSTRACT FROM AUTHOR]

Developing high-efficient and Earth-abundant electrocatalysts toward hydrogen evolution reaction (HER) is strongly desired for electrochemical water splitting but remains a considerable challenge. Herein, we propose a 3D hierarchical Fe(PO 3) 2 @Cu 3 P heterostructure nanotube arrays on Cu foams for promising HER catalysts. The HER performance can be tuned by changing FeCl 3 concentrations and the optimized cathode exhibits excellent HER activity in 1 M KOH with a low overpotentials of 108 mV @ 10 mA cm−2 and a small Tafel slope of 84 mV dec−1. Furthermore, this electrode delivers high electrochemical durability with stable operation for 24 h. Such high performance can be ascribed to the unique hierarchical heterostructure with large electrochemical surface area, synergistic effect and fast electron transport. Our study can provide new inspiration for rational construction of copper-based hierarchical nanomaterials for HER electrodes and other energy-related applications. Hierarchical Fe(PO 3) 2 @Cu 3 P nanotube hybrids on 3D copper foam were synthesized, which demonstrate excellent activity toward hydrogen evolution in alkaline solution with robust stability. Image 1 • Hierarchical Fe(PO 3) 2 @Cu 3 P nanotube arrays were successfully synthesized on Cu foam. • The hybrid catalysts exhibit excellent activities for HER in alkaline media. • Synergistic effect between Fe(PO 3) 2 and Cu 3 P was found by XPS. • The hybrid catalyst exhibits considerable stability for HER. [ABSTRACT FROM AUTHOR]