This research aimed to study the effects of chitosan on physiology, photosynthesis and biomass of rice cultivar RD47 under elevated ozone. Rice samples were grown at indoor climate controlled chambers, allowing the inlet air to pass through charcoal filters. For combined effects of chitosan and ozone, rice was soaked and sprayed with chitosan 0.05% (W/V) under elevated ozone concentration at 40 ppb (Chi+EO 3 40) and 70 ppb (Chi+EO 3 70). Control groups (CF) with no additional ozone were also studied. Samples were analyzed weekly for tiller number per plants, leaf area, leaf chlorophyll, photosynthesis, shoot biomass, root biomass and total biomass. The results obviously showed that ozone at the concentration of both 40 and 70 ppb caused negative effects on rice physiology, photosynthesis and biomass. The 70 ppb concentration, particularly, caused sever damage. Whilst soaking and spraying with chitosan could significantly reduce the harmful effects of ozone compared with the control group. For the samples soaked and sprayed with chitosan under elevated ozone for 21 days, Chi+EO 3 40 and Chi+EO 3 70 significantly performed more photosynthesis and contained more leaf chlorophyll than EO 3 40 and EO 3 70, respectively (p ≤ 0.05). In addition, chitosan could reduce the ozone negative effects and increased higher physiology and photosynthesis rate. However, there was no significant difference in biomass compared with the control group. Even through, ozone has been gradually increasing which made plants at risk, chitosan treatment could significantly ameliorate the effect of ozone and serve as a plant growth promoter with no harmful to human being.

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Engineered nanoparticles (ENPs) are reported as potentially response to rice physiological and production. The research aimed to investigate the effects of suspended nano-titanium dioxide (sn-TiO2), which is non-toxic to ecology and on the physiology and yield of Thai rice. Selected rice cultivars of RD41 were soaked and sprayed with three difference concentrations of sn-TiO2 (T0.01, T0.02, T0.03 and C) through growing period. Tiller number per plants, stem height and leaf chlorophyll of rice RD41 cultivars were analyzed at tillering (40 days), flowering (70 days), and final harvesting (100 days), whereas the biomass and yield were evaluated at final harvesting (100 days). The results showed the concentration of T0.03 had highest effects on rice RD41 for all studies, which showed non-significance of differences at p <0.05 compared to T0.02. Application of T0.01, T0.02 and T0.03 treatments increased total biomass 33.69, 42.66 and 47.91 g plant -1, respectively, compared to control (30.49). Application of T0.02 enhanced the plant growth and caused increases in the yield of rice, which impacted food availability. According to the results obtained, the function of sn-TiO2 played a positive role in many aspects. For instance, sn-TiO2 could increase light harvesting to activate the photosynthesis rate of rice RD41. Besides, nitrogen metabolism was improved by sn-TiO2 and stimulated protein and pigments content. Moreover, our observed decreasing in injury indices compared to the control group, which caused improvement in cell enlargement, cell elongation and plant growth. Atomic absorption spectrometric result ensured that there is no unforeseen Ti contamination in all part of rice. These findings are important supplementary factors to the application of sn-TiO2 for the crop yield and quality with a proper concentration for their benefits potential.

Platinum/carbon doped titanium dioxide/single-walled carbon nanotubes (Pt/C/TiO2/SWNTs) were successfully prepared by blending method. These composite catalysts were found to exhibit an anatase TiO2 structure with uniform Pt/C and the existence of SWNTs can be confirmed by transmission electron microscopy (TEM). The composite of Pt/C with TiO2/SWNTs could improve an enhancement in catalytic properties upon applying TiO2/SWNTs as catalyst support. The catalytic oxidation of methanol of Pt/C doped TiO2/SWNTs is found to be higher as compared to the undoped and Pt/C doped materials.

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