Uv 2800a spectrophotometer

The visible-light driven photocatalytic properties of the as-synthesized samples were assessed by Rh B degradation coupled with H₂ production. A 300 W Xe lamp (λ > 420 nm) was chosen as the radiation source and ultrapure water was employed throughout the experiments.
In a typical degradation experiment, 50 mg of the photocatalyst was fully mixed with 100 mL of Rh B (10 mg L⁻¹) by ultrasonic treatment for 5 min. Before exposure to light, the reaction system achieved adsorption–desorption equilibrium by magnetic stirring for 30 min in darkness. At designated intervals, 3.0 mL suspension was collected and centrifuged at 12 000 rpm for 10 min. Finally, the concentration of Rh B in the supernatant was estimated using a Unico UV-2800A spectrophotometer at the characteristic wavelength of 552 nm.
In the photocatalytic H₂ generation test, 30 mg of sample deposited with 1.0 wt% Pt was fully suspended into 50 mL ultrapure water containing 10% (vol/vol) triethanolamine (TEOA), where TEOA was used as the hole scavenger and Pt was used as the co-catalyst. H₂ evolution during the photocatalytic reaction was calculated using an online gas chromatograph (Agilent, GC-8890) equipped with a thermal conductivity detector and high-purity nitrogen was used as the carrier gas.

After growth for 20 d, the numbers of floating leaves, submerged leaves and rolled leaves from each cup were counted. After 40 d, 7 largest floating leaves from each light treatment were harvest, weighed for the fresh weight of each leaf (M), scanned to obtain the single leaf area (S), and then the specific leaf weight was calculated as SLW = M/S (Mishanin et al. 2016 (link)). The pigments of the same leaf samples were extracted by 80% acetone after rapid homogenization, and the concentrations of chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoid (Cars) were measured by UV-2800A spectrophotometer (UNICO, USA), using the method of Lichtenthaler and Wellburn (1983) .