“…The residual H 2 O 2 concentrations were measured after immersion times of 1, 2, 5, 10, 30, 60, 120, 240, and 360 min to obtain the decomposition curves. The method for measuring the H 2 O 2 concentration was the same as that reported in a previous article [16]. The optical absorbance of a H 2 O 2 solution, colored using diluted (5 wt%) titanium sulfate (Ti(SO 4 ) 2 ; 30 wt%, Fujifilm Wako Pure Chemical), was measured using a deuterium-halogen and tungsten lamp (DH-2000, Ocean Optics, Largo, FL, USA), a fiber multichannel spectrometer (HR-4000, Ocean Optics), and optical fiber (P600-1-UV/VIS, Ocean Optics).…”