UV Photocatalytic Activity for Water Decomposition of SrxBa1−xNb2O6 Nanocrystals with Different Components and Morphologies

Guoqiang Han,Bo Lin,Shuguang Cao

doi:10.1155/2017/2163608

Abstract

Strontium barium niobate SrxBa1-xNb2O6 (SBN) nanocrystals with different components (x=0.2, 0.4, 0.6, and 0.8) were synthesized by Molten Salt Synthesis (MSS) method at various reaction temperatures (T = 950°C, 1000°C, 1050°C, and 1100°C). The SBN nanocrystals yielded through flux reactions possess different morphologies and sizes with a length of about ~100 nm~7 μm and a diameter of about ~200~500 nm. The Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) techniques were used to study the compositions, structures, and morphologies of the nanocrystals. The absorption edges of the SBN nanocrystals are at a wavelength region of approximate 390 nm, which corresponds to band-gap energy of ~3.18 eV. The SBN nanocrystals with different sizes display different photocatalytic activity under ultraviolet light in decomposition of water. The SBN60 nanocrystals exhibit stable photocatalytic rates (~100~130 μmol of H2·g−1·h−1) for hydrogen production. The SBN nanocrystals can be a potential material in the application of photocatalysis and micro/nanooptical devices.

Highlights

The synthesis of nanostructures has attracted extensive attention in the past two decades due to their novel size-dependent properties
The absorption edges of the SBN nanocrystals are at the wavelength region of approximate 390 nm and the bandgap of SBN crystal is about 3.18 eV at room temperature
The SBN nanocrystals are synthesized as single-crystal particles with sizes of ∼100 nm∼7 μm through changing component and reaction temperature

Summary

Introduction

The synthesis of nanostructures has attracted extensive attention in the past two decades due to their novel size-dependent properties. The strontium barium niobate SrxBa1−xNb2O6 (SBN) nanocrystals have exhibited a variety of ferroelectricity [2,3,4], photorefractive [5], electrooptic, nonlinear optical [1, 6], and thermoelectric properties [7] which are potentially important for many applications in various fields. The advantage of SBN nanocrystals is generally attractive for some device applications, such as thin film devices [2], optical sensors [8], and piezoelectric ceramic resonators [9]. SBN nanocrystals with varied compositions can be fabricated into different sizes and complex shapes through low-cost and easy methods such as template-assisted synthesis and template-free synthesis, Czochralski method, dual-stage sintering method, and low-temperature combustion synthesis process [10,11,12,13]. Synthesis of more efficient light-driven SBN nanocrystals with complex morphologies is a subject of considerable research interest

Experimental

Results and Discussion

Conclusions