Where h, ν, α, A, n, and Eg were Planck's constant, light frequency, absorption coefficient, constant, n =2, and bandgap, respectively. The wavelength obtained from UV-Vis spectra in nm was converted to photon energy (hν) using the equation hν = 1240/λ. Thermogravimetric analysis (TGA) was recorded using the TA 60 thermal analyzer apparatus (Shimadzu, Japan) with a heating rate of 10 °C•min -1 . The specific surface area was determined using N2 adsorption-desorption isotherm (Quantachrome Instrument Corporation, Nova 3200, USA) using the Brunauer-Emmett-Teller (BET) method. The pore size distributions for mesopore and micropore regimes were determined via Density Functional Theory (DFT) and the Horvath Kawazoe (HK) method. The photoluminescence (PL) spectra were recorded using a fluorescence spectrophotometer (Cary Eclipse, Agilent USA). The emission for hydroxy-terephthalic acid (TPA-OH) was measured at excitation wavelength 315 nm. Gas chromatography-mass spectrometry (GC-MS) was evaluated using Shimadzu 2014 (Japan) equipped with ShinCarbon ST micro packed column (Restek, length 2 m × ID 2mm, USA) and mass spectrometer.