Fabrication and surface photovoltage study of hematite microparticles with hollow spindle-shaped structure

Hematite (α-Fe2O3) particles with hollow spindle-shaped microstructure were successfully synthesized by a one-pot hydrothermal approach in large scale. The structural properties of the sample were systematically investigated by X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray spectrum, high resolution transmission electron microscopy, selected-area electron diffraction techniques, UV-vis diffuse reflectance spectroscopy and infrared spectroscopy techniques. The characterization results revealed that the α-Fe2O3 microparticles with a single-domain crystalline structure was mainly grown along the (1 0 4) crystal plane. The valence states and the surface chemical compositions of α-Fe2O3 were further identified by X-ray photoelectron spectroscopy. The feature of photo-induced charge separation on spectrum was demonstrated by the surface photovoltage measurement under different external biases. The observed photoelectric characteristics of the as-fabricated material are beneficial for various optical and electronic applications.