The optical properties of the samples have been studied carefully, and photochemical reduction tests of Cr(VI) ions are demonstrated.
Thus, the as-prepared UCNPs@[Zn.sub.0.5][Cd.sub.0.5]S YSN would exhibit good NIR-mediated photochemical reduction or oxidation performance.
Caption: Figure 5: (a) UV-Vis spectra of the UV-Vis absorbance spectra of the Cr(VI) complex, showing the photochemical reduction ability of the UCNPs@[Zn.sub.0.5][Cd.sub.0.5]S YSN towards photocatalytic reduction of Cr(VI) at given irradiation times using a Xe lamp.
Besides many process being employed for the preparation of nanoparticles including aerosol technologies, laser ablation, lithography, photochemical reduction
, ultrasonic fields, ultraviolet irradiation techniques etc.
Recently, studies on C[O.sub.2] photochemical reduction by Ti[O.sub.2] have been carried out from the viewpoint of performance promotion by extending absorption range towards visible region [11-15].
There are six vital C[O.sub.2] conversions: chemical conversions, electrochemical reductions, biological conversions, reforming, inorganic conversions, and photochemical reductions [2, 3].
Generally, metal nanoparticles can be prepared and stabilized by physical and chemical methods; the chemical approach, such as chemical reduction, electrochemical techniques, and photochemical reduction
is most widely used (1,2).
These include CO2 hydrogenation, dry reforming of CO2 with natural gas, electrochemical and photochemical reduction
(1998), 1 mol of photons causes excitation 1 umol electrons of the chlorophyll in this condition, it appears that the efficiency of photosystem II ([PHI]PSII) represents the proportion of these electrons that are used during photochemical reduction
of [NADP.sup.+.] The cultivars 'Palmer' and 'Uba' showed the greatest reduction in [PHI]PSII, while 'Haden' and 'Tommy Atkins' showed tolerance up to a concentration of 15 mmol [L.sup.-1] NaCl (Figure 3B).
Nonenzymatic photochemical reduction
of nitrate (Naik et al., 1976) may be ruled out, because even in 28-d-old seedlings (0 DAT), which were also exposed to sunlight, nitrite production could hardly be detected.