Search

Abstract: Silver antimonite samples with different Ag/Sb ratios were prepared via ion exchange method through the mediator of silver proton-exchanged compounds. With the rise in the ratio of Ag to Sb in the samples, the optical band gap decreases due to the increasing contribution of Ag4d to the valence band; the surface photovoltage decreases and photocatalytic activity increases due to surface states related to the Sb3+ in the samples. The present results indicate that appropriate amount of Sb3+ is favorable for improving the photocatalytic activity under visible light irradiation. [Copyright &y& Elsevier]

Abstract: N-doped TiO2/C3N4 composite samples were synthesized by heating the mixture of the hydrolysis product of TiCl4 and C3N4 at different weight ratios. The samples were characterized by X-ray diffraction (XRD), Raman spectrum, UV–vis absorption spectrum, photoluminescence spectrum, X-ray photon electron spectrum (XPS) and surface photovoltage spectrum (SPS). The XRD and Raman results indicate that the introduction of C3N4 could inhibit the formation of rutile TiO2. The composite samples show slight visible light absorption due to the introduction of C3N4. The XPS result reveals that some amount of nitrogen is doped into TiO2, and C3N4 exists in the composite sample. The intensities of the SPS signal in the composite samples decrease with the rise in the amount of C3N4 in the samples. The photocatalytic activity was evaluated from the Rhodamine B (RhB) degradation under fluorescence light irradiation. The composite samples show significantly enhanced photocatalytic activities and the RhB self-sensitized photodegradation in this system was observed by measuring the photocurrent in the dye sensitized solar cell using the composite as the working electrode. [Copyright &y& Elsevier]

Abstract: NaNbO3, (AgNbO3)0.5(NaNbO3)0.5 and AgNbO3 films on FTO conducting glass substrates were fabricated by pulsed laser deposition at 973K for 1h under 10Pa oxygen pressure with the laser energy of 400mJ. The energy band structure and photoelectrochemical behavior were investigated by measuring the flatband potential (V fb) and photocurrent. The optical band gaps for NaNbO3, (AgNbO3)0.5(NaNbO3)0.5 and AgNbO3 are 3.50, 3.25 and 2.93eV, respectively. And the V fb for the NaNbO3, (AgNbO3)0.5(NaNbO3)0.5 and AgNbO3 films are −0.91, −0.76 and −0.88V (vs. Ag/AgCl), respectively, indicating that the conduction band bottom of (AgNbO3)0.5(NaNbO3)0.5 is more positive than those of NaNbO3 and AgNbO3, and the valence band top becomes more positive in order of AgNbO3, (AgNbO3)0.5(NaNbO3)0.5 and NaNbO3. The AgNbO3 film shows the largest photocurrent density due to the more light harvesting, the relative higher donor density and large contact surface area between the electrode and the electrolyte solution. The (AgNbO3)0.5(NaNbO3)0.5 film shows lowest photocurrent due to lower donor density. [Copyright &y& Elsevier]