Photocatalytic Degradation of Polycyclic Aromatic Hydrocarbons in Water by 3D Printed TiO₂ Composites

Abstract

Recent progress in developing composites embedded with photocatalysts indicates application for wastewater treatment. However, significant gaps remain in developing effective photocatalyst−polymer composites for use as customizable, deployable, and retrievable structures for mitigating environmental contamination. The goal of this study was to generate and evaluate the performance of 3D printed TiO 2 composites for degrading polycyclic aromatic hydrocarbons (PAHs) in waters affected by contaminated sediment. Photocatalytic structures were fabricated using polylactic acid (PLA) compounded with TiO 2 nanoparticles as filament feedstock and printed using a benchtop 3D printer. Photocatalysis and photolysis experiments were conducted in controlled environmental chambers under full spectrum light (λ = 280−750 nm). 3D printed PLA-TiO 2 disks increased the degradation kinetics (compared to photolysis) of a complex mixture of 4to 5-ring PAHs achieving nondetectable concentrations within hours to days. The PAH removal rate was relatively rapid, with 3D printed PLA-TiO 2 treatments achieving degradation half-lives within ∼6 to ∼24 h. After 48 h of treatment, both photolysis and photocatalysis eliminated toxicity to Ceriodaphnia dubia. These data indicate the potential application of 3D printable photocatalytic polymers to mitigate problematic organic constituents in water and highlight the benefits of additive manufacturing to rapidly prototype and optimize innovative structures.

Additives influence 3D printer emission profiles: Implications for working safely with polymer filament composites

“…Filaments were then mounted vertically onto SEM stubs with carbon tape and supported with thermoplastic adhesive. TiO 2 concentration was measured for relevant filaments via thermogravimetric analysis (TGA) as performed on the fabricated filament according to previously described methods 25 …”

“…A complete list of tested filaments along with relevant details is provided in Table 1. Two filaments were custom made at the US Army Engineer Research and Development Center (ERDC) in Vicksburg, MS using a twin screw extruder (Process 11, Thermo Fisher, 567-7000) using previously described methods [24][25][26] ; natural PLA pellets were used as the base material (3DXTech, Grand Rapids, MI, USA) and TiO 2 nanoparticles (Aeroxide P25, Evonik, NJ; 19 nm, SSA 35-65 m 2 /g) as the additive filler.…”

Effective photocatalytic degradation of rhodamine-B over Zn-doped BaO2 and SrO2 composites under UV and sunlight irradiation

“…18–20 Among all semiconductor metal oxides, SnO 2 , 21 ZnO 2 , 22 CeO 2 , 23 SiO 2 , 24 MnO 2 , 25 ZrO 2 , 26 and TiO 2 (ref. 27 and 28) are described as developing photocatalysts due to their excellent photocatalytic activity. To improve photocatalytic performance, many researchers focus on metal or nonmetal doping, surface modification, heterostructure formation, and composite materials.…”

Degradation of Model Compounds by 1O2-Generating Photosensitizer–Doped Membranes

“…Ideally, other technologies such as photoactive coatings would be an eco-friendlier process. ,, As photoactive coatings able to disinfect wastewater to a “safe to drink” level are not known, we have taken advantage of this opportunity to develop membranes doped with PSs known to generate the reactive oxygen species SO. − While not demonstrated here, membranes such as the ones discussed below can possibly be used as surface coatings in water treatment facilities and decrease the amounts of chlorine required.…”