Role of Oil Palm Empty Fruit Bunch-Derived Cellulose in Improving the Sonocatalytic Activity of Silver-Doped Titanium Dioxide

Abstract

In this study, a novel cellulose/Ag/TiO2 nanocomposite was successfully synthesized via the hydrothermal method. The cellulose extracted from oil palm empty fruit bunch (OPEFB) could address the disposal issue created by OPEFB biomass. Characterization studies such as FESEM, EDX, HRTEM, XRD, FTIR, UV–Vis DRS, PL, XPS, and surface analysis were conducted. It was observed that the incorporation of cellulose could hinder the agglomeration, reduce the band gap energy to 3 eV, increase the specific surface area to 150.22 m3/g, and lower the recombination rate of the generated electron-hole pairs compared to Ag/TiO2 nanoparticles. The excellent properties enhance the sonocatalytic degradation efficiency of 10 mg/L Congo red (up to 81.3% after 10 min ultrasonic irradiation) in the presence of 0.5 g/L cellulose/Ag/TiO2 at 24 kHz and 280 W. The improvement of catalytic activity was due to the surface plasmon resonance effect of Ag and numerous hydroxyl groups on cellulose that capture the holes, which delay the recombination rate of the charge carriers in TiO2. This study demonstrated an alternative approach in the development of an efficient sonocatalyst for the sonocatalytic degradation of Congo red.

Tailoring visible-light active TiO2/cellulose nanocomposites with controlled crystalline structure for enhanced photocatalytic performance

“…The PL spectra of all samples exhibited emissions peaks at 411 and 475 nm, which can be described as the self-trapped excitons in TiO 6 octahedral and the presence of oxygen vacancies in the TiO 2 nanoparticles, respectively 62 . The peak of eucalyptus pulp corresponds to a report by Yi Ding Chai et al that the broad PL spectra of cellulose appeared at 450–650 nm 63 . The unique emission behaviors of cellulose were thought to originate from the electron-rich oxygen and/or glucose units, which also confirmed the aggregation-induced or crystallization-induced emissions from cellulose 63 , 64 .…”

“…The peak of eucalyptus pulp corresponds to a report by Yi Ding Chai et al that the broad PL spectra of cellulose appeared at 450–650 nm 63 . The unique emission behaviors of cellulose were thought to originate from the electron-rich oxygen and/or glucose units, which also confirmed the aggregation-induced or crystallization-induced emissions from cellulose 63 , 64 . It can be seen that all the samples showed similar peaks of PL while the intensity of PL spectra tended to decrease when TiO 2 was immobilized on cellulose.…”

“…The cellulose-mixed exhibited a lower PL intensity when compared with the cellulose-anatase and the cellulose-rutile. This result indicated that the cellulose-mixed had lower recombination of electron–hole pairs, which caused the electron and the hole to react with oxygen and water to produce highly reactive oxygen species that degraded pollutants via the oxidation processes 63 , 65 . The lower recombination of the cellulose-mixed could be due to the mixed phase anatase and rutile causing a lower energy band gap, hence a higher photocatalytic activity of RhB degradation.…”

Preparation of high-crystalline and non-metal modified g-C3N4 for improving ultrasound-accelerated white-LED-light-driven photocatalytic performances

“…Absorbed energies (Eqs. ( 3 )–( 14 )) 4 , 8 , 9 , 64 – 66 . To ensure sufficient mineralization of the organic content, the use of boosters i.e., sufficient oxygen injection and spontaneous temperature increase during sonication can synergistically accompany each other to improve DEM and TOC decomposition (Fig.…”