“…48,70 The peaks at 1162, 1072, and 881 cm −1 are ascribed to stretching vibration of the C─N and C─N + groups; on the other hand, the peaks at 2925 cm −1 (N─H), 1545 cm −1 (C═C), 1440 cm −1 (C─C), 1209 cm −1 (C─C), 987 cm −1 (C═C), 828 cm −1 (C─H), and 779 cm -1 (C─H) are attributed to PPy stretching modes. 59,74,75 After deposition of PPy layers onto the surface of filter paper, the composite membrane shows a near-zero transmission value and a low reflection (approximately 20%) in the entire solar spectrum, as shown in Figure 2B, and the solar absorption ratio is estimated by the following equation: 73 The Raman spectra of PCP and pure PPy particles exhibits the characteristic Raman shifts of PPy as shown in Figure 2A, such as 1592, 1497, 1376, 1239, 1088, 973, and 937 cm −1 .…”