Dependence of photocatalytic activity on structural and optical properties of nanocrystalline ZnO powders

Synthesis of hierarchical SnO2 nanoflowers and their high gas-sensing properties

“…During the growth process, three chemicals (sodium citrate, PVP and NH 3 Á H 2 O) affect the morphology growth greatly. As a weak alkaline solution, NH 3 Á H 2 O can release OH -, which reacts with Sn 2 þ , dominates the formation of the final SnO 2 nanoflowers [11]. Thus, the overall reaction for the growth of SnO 2 crystals may be expressed by the following equations:…”

Structural- and optical-property characterization of three-dimensional branched ZnO nanospikes

“…in which α is absorption coefficient of the semiconductor, E is photon energy that derived from the product of planck constant and speed of light, C is the proportionality constant that is related to the effective masses associated with the balance and conduction bands, E g is the bandgap energy and n is the type of transition (n = 1/2 for direct transition while n = 2 for indirect transition; n in current study is taken to be 2 due to the reason that ZnO is a semiconductor with direct transition) [54]. The absorption coefficient, α can be calculated by using Beer-Lambert law,…”

Synthesis of porous small-sized ZnO nanoparticles and their gas-sensing performance

“…Hydrothermal synthesis reactor provides a favorable reaction environment and is beneficial to process full of chemical reactions to obtain uniform NPs. The chemical reactions mentioned are as follows [10].…”