BACKGROUNDThe effects of the environment and genotype in the coffee bean chemical composition were studied using 9 trials covering an altitudinal gradient (600 -1100 m.a.s.l) with 3 genotypes of Coffea arabica in the Northwest mountainous region of Vietnam. The impacts of the climatic conditions on bean physical characteristics and chemical composition were assessed. RESULTSWe showed that the environment had a significant effect on the bean density and on all bean chemical compounds. The environment effect was stronger than the genotype and genotype-environment This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record. Please cite this article as

TiO2 thin films were synthesized by using Chemical Vapor Deposition (CVD) method on different substrates, such as glass, aluminium foil , and ceramic. The samples had been characterized by microscopy analysis, SEM, and EDS. The results show that TiO2 thin films were successfully fabricated and TiO2 nanocrystals with size of 50-100 nm loaded uniformly on surface of different substrates. The photocatalytic activities of all samples were investigated in photo-degradation of methyl orange (MO) under UV light irradiation and was followed by the UV-Vis diffuse reflectance spectroscopy, showing that the conversion of methyl orange achieved the highest percentage of 91% with TiO2 thin film synthesized on the ceramic substrate over 270 minutes of reaction. The hypothetical mechanism explaining this observation is that the surface morphology of ceramic plays a major role in the augmentation of MO molecules adsorption onto the surface of material, thus, improves the dye degradation process.