Premium
Preparation of floatable TiO 2 /poly(vinyl alcohol)‐alginate composite for the photodegradation of ammonia wastewater
Author(s) -
Zendehzaban Masoud,
Ashjari Mohsen,
Sharifnia Shahram
Publication year - 2019
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.5072
Subject(s) - photocatalysis , vinyl alcohol , fourier transform infrared spectroscopy , photodegradation , materials science , chemical engineering , diffuse reflectance infrared fourier transform , visible spectrum , nuclear chemistry , chemistry , catalysis , polymer , organic chemistry , composite material , engineering , optoelectronics
Summary The use of floatable photocatalyst supports is an operable strategy of increasing photocatalytic performance in terms of improving light absorption. In this work, floatable organic support based on poly(vinyl alcohol) (PVA) was used to float commercial TiO 2 P25 nanoparticles. At first, by the use of CaCl 2 and boric acid at pH 3 the cross‐linking of PVA blended with sodium alginate (PVA‐Alg) was improved to enhance chemical and mechanical stability, and then it was chemically modified by trimethylchlorosilane to achieve floatable organic support (modified or MPVA‐Alg). The prepared support and photocatalyst were characterized by X‐ray diffraction (XRD), Fourier‐transform infrared spectroscopy (FTIR), scanning electron microscopy, energy‐dispersive X‐ray spectroscopy (EDX)‐elemental mapping, inductively coupled plasma optical emission spectroscopy, ultraviolet‐visible (UV‐vis) diffuse reflectance spectroscopy, photoluminescence (PL), thermalgravimetry, Brunauer‐Emmett‐Teller (BET), and water contact angle (WCA) analyses and applied for the ammonia degradation under UV to visible regions. Results of WCA and FTIR confirmed that chemical modification of PVA‐Alg led to lowering hydrophilicity to be floated on the ammonia wastewater. UV‐vis analysis indicated that the MPVA‐Alg acts as a light absorbent in UV‐vis ranges and makes TiO 2 /MPVA‐Alg a visible light active composite. Also, the PL analysis showed that the charge recombination process was strongly suppressed in the case of the TiO 2 /MPVA‐Alg sample. BET theory suggested that the textural properties were not the key factor in determining photocatalytic performance. The maximum photocatalytic ammonia removal was obtained to be 63% and 57% by the TiO 2 /MPVA‐Alg composite under UV‐vis light irradiations, respectively. The MPVA‐Alg and TiO 2 exhibited the ammonia degradation of 28.5% and 15.2% under visible and 29.4% and 40.0% under UV irradiation, respectively. The TiO 2 /MPVA‐Alg showed favorable reuse ability after five runs due to desirable chemical and mechanical resistance. This study provides an insight into the modification of polymeric structures to be used as both floatable photocatalyst support and light sensitizer.