Engineering Commercial TiO2 Powder into Tailored Beads for Efficient Water Purification

Abstract

In this study, efficient commercial photocatalyst (Degussa P25) nanoparticles were effectively dispersed and stabilized in alginate, a metal binding biopolymer. Taking advantage of alginate’s superior metal chelating properties, copper nanoparticle-decorated photocatalysts were developed after a pyrolytic or calcination-sintering procedure, yielding ceramic beads with enhanced photocatalytic and mechanical properties, excellent resistance to attrition, and optimized handling compared to powdered photocatalysts. The morphological and structural characteristics were studied using LN2 porosimetry, SEM, and XRD. The abatement of an organic pollutant (Methyl Orange, MO) was explored in the dark and under UV irradiation via batch experiments. The final properties of the photocatalytic beads were defined by both the synthesis procedure and the heat treatment conditions, allowing for their further optimization. It was found that the pyrolytic carbon residuals enabled the adhesion of the TiO2 nanoparticles, acting as binder, and increased the MO adsorption capacity, leading to increased local concentration in the photocatalyst vicinity. Well dispersed Cu nanoparticles were also found to enhance photocatalytic activity. The prepared photocatalysts exhibited increased MO adsorption capacity (up to 3.0 mg/g) and also high photocatalytic efficiency of about 50% MO removal from water solutions, reaching an overall MO rejection of about 80%, at short contact times (3 h). Finally, the prepared photocatalysts kept their efficiency for at least four successive photocatalytic cycles.

Tungsten Oxide Morphology-Dependent Au/TiO2/WO3 Heterostructures with Applications in Heterogenous Photocatalysis and Surface-Enhanced Raman Spectroscopy

“…21-1272) and 11% rutile (JCPDS card no. 21-1276), as expected [28,29]. Au/TiO 2 /WO 3 -HW-HA and Au/TiO 2 /WO 3 -HW-TA samples presented mixed crystal phases of WO 3 , that is, WO 3 •0.33H 2 O partial hydrate (JCPDS card no.…”

Novel Pilot-Scale Photocatalytic Nanofiltration Reactor for Agricultural Wastewater Treatment

“…Hence, the cumulative adsorbed LN 2 volume at 0.97 P/P 0 corresponded to the pores formed due to the close-packing of spherical TiO 2 nanoparticles having a high number of contact points; whereas the volume adsorbed at the P/P 0 interval between 0.97 and 0.99, was associated with the empty space between larger TiO 2 nanoparticles aggregates (macropores) [ 24 ].…”

“…The specific surface area (S BET ) was calculated by the Brunauer–Emmett–Teller (BET) method, while the pore size distribution was determined by the Barrett–Joyner–Halenda (BJH) method based on a modified Kelvin equation and the non-local density functional theory (NLDFT) methods. The average pore size (nm) was calculated from the porosimetry results as 4000·TPV/S BET [ 24 ] and the mean particle size (nm) as 6000/S BET ·d sample [ 24 ], where TPV is the total pore volume and d sample is the density of the sample, assuming cylindrical pore geometry of the empty space between the packed, spherical TiO 2 nanoparticles.…”

Degradation of Organic Methyl Orange (MO) Dye Using a Photocatalyzed Non-Ferrous Fenton Reaction

“…However, as the reaction time continued, annTNA provided the superior MO degradation kinetics, indicating that the catalytic activity of titania increases with less rutile in the titania material. Romanos et al modified commercial P25 with well-dispersed Cu nanoparticles, and the system was found to degrade 50% of 12 ppm initial dye after exposure to UV light in the 350–390 nm range for 3 h [ 69 ]. In another process, a bulk P25 composite using Posidonia oceanica fibers showed 100% degradation of phenol after 4 h of UV light irradiation [ 70 ].…”