Table 1 Assignments of the FT-IR absorption bands of SA, TiO₂NPs, SA/TiO₂, CPT and CPT-SA/TiO₂

SA

3460

OH stretching

2922

CH₂ asymmetric stretching

1620

(–COONa) asymmetric stretching

1418

(–COONa) symmetric stretching

1305

C–O asymmetrical stretching

1030

C–O–C stretching vibrations

900–600

C–H stretching vibrations

TiO₂ NPs

3435

OH stretching

2928

C–H stretching vibrations

1631

OH bending vibration of adsorbed water molecules

1383

Ti–O–Ti stretching vibrations

555

Ti–O stretching vibrations

SA/TiO₂

3440

OH stretching

1635

(–COONa) asymmetric stretching

1418

(–COONa) symmetric stretching

1030

C–O–C stretching vibrations

670

Ti–O stretching vibrations

CPT

3438

OH stretching

1666

C=O stretching

1444

C=N stretching

1113

C–C(=O)–O stretching

1035

C–O stretching

613

Hydrogen bonds on the heteroaromatic nucleus

CPT-SA/TiO₂

3459

OH stretching

1635

(–COONa) asymmetric stretching

724

Ti–O stretching vibrations