Preparation of Bi3.64Mo0.36O6.55 by Reflux Method and Its Application in Photodegradation of Organic Pollution

Bismuth molybdate (γ-Bi2MoO6) photocatalyst has drawn numerous attentions in the field of photocatalysis because of its band gap (2.5eV ~ 2.8eV) and good visible light response (420 ≤ λ ≤ 500 nm). However, as a kind of bismuth molybdates, there are still few studies on Bi3.64Mo0.36O6.55 (BMO), thus further exploration is needed. Herein, a simple reflux method was developed to synthesize the cubic phase BMO. This method is simple and easy to operate under atmospheric pressure, showing the great potential for large-scale production. In contrast with the nanosheet structure of Bi2MoO6, the morphology of BMO is mixture of nanorod and nanoparticle-like structure. The Motts curves show that conduction band position and the valence band position of BMO was 2.77 eV, -0.33eV and 2.44eV, respectively. A new mixed phase of 3Bi2O3•2MoO3 was appeared in BMO crystal, showing that the phase transition of BMO began at 400℃. When BMO was calcined at 300℃, photocatalytic degradation rate is up to maximu. The photocatalytic activity of visible-light range was tested and compared with γ-Bi2MoO6. BMO had a better photodegradation activity than that of the Aurigillius phase γ-Bi2MoO6 due to its larger band gap and the strong oxidation ability.

Electrical and optical studies on tungsten-substituted bismuth molybdates

This manuscript highlights the structural, electrical and optical properties of Bi2Mo1-xWxO6 (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) compounds. These compounds were prepared employing the citrate sol-gel method. These compositions were characterized using thermo-gravimetric and differential scanning calorimetry, X-ray diffraction and infrared techniques. The Rietveld refinements of X-ray powder diffraction data determined and confirmed the crystal structure of the compositions. DC electrical conductivity indicated the conduction behaviour and diffuse reflectance spectroscopy confirmed the semiconducting nature of the compounds. Room temperature photoluminescence results exhibited two type of emission namely blue-green and green emission in the visible region.