Table 6.

Abiotic degradation of MPs.

Degradation technology	Degradation mechanism	Types of MPs	Degradation efficiency	Reference
Hydroxy-rich ultrathin BiOCl (BiOCl−X) degrades MPs	Photocatalytic degradation	200–250 μm HDPE microspheres (PE−S), 2.38 mm Nylon-66 MPs, 3 mm POM microspheres, 2.6 mm white PP microspheres, 3 mm red PP microspheres, 5 mm black PP microspheres, 4 mm recycled HDPE	PE-S mass loss 5.38% (BiOCl−1); PE−S mass loss 0.22% (BiOCl)	[139]
ZnO–Pt nanocomposite photocatalysts degrades MPs	Photocatalytic degradation	LDPE film	N/A	[140]
visible light photocatalysis of NPs using anodized CuxO	Visible-light photocatalytic degradation	9 mg mL−1 PS−NPs solutions	The concentration of PS−NPs was reduced by 23% after 50 h	[141]
TiO2 nanoparticle film made with Triton X−100	Photocatalytic degradation	400 nm PS	Mineralization 98.40% of 400 nm PS in 12 h	[142]
Photocatalysis with TiO2–P25/β−SiC foams under UV-A radiation	Photocatalytic degradation	Three monodisperse suspensions of nanobeads:105 nm PMMA nanobeads; 140 nm PS nanobeads; 508 nm PS nanobeads	N/A	[143]
Poly(styrene-block-acrylic acid) containing TiO2 gel (PS−b−PAA/TiO2) polymer could provoke photocatalytic activity to PS particles in water	Photocatalytic degradation	PS containing a N–H type hindered amine light stabilizer (PS/LA-77) in water	The molecular weight decreases were from 10% to 11%	[144]
Green photocatalysis using a protein-based porous N–TiO2 semiconductor	Photocatalytic degradation	Extracted from a commercially available exfoliating scrub with diameters ranging 700–1000 μm	A total mass loss of 1.85% during the first 16 h of irradiation	[145]
Mesoporous N–TiO2 coating	Photocatalytic degradation	Primary HDPE and LDPE MPs of two sizes were obtained from two commercial facial scrubs of different brand	Mass Loss (%): HDPE_A: 0.22 ± 0.02; HDPE_B: 4.65 ± 0.35; (5 ± 0.01) mm × (5 ± 0.01) mm LDPE: 0.97 ± 0.32; (3 ± 0.01) mm × (3 ± 0.01) mm: 1.38 ± 0.13	[137]
Electro-Fenton like (EF-like) technology based on TiO2/graphite (TiO2/C) cathode	Cathodic reduction dechlorination and hydroxyl radical (Oradical dotH) oxidation simultaneously	100–200 μm PVC−MPs	Degrade PVC−MPs with 56 wt % removal after potentiostatic electrolysis at −0.7 V vs. Ag/AgCl at 100 °C for 6 h	[148]
Hydrothermal coupled Fenton system	Thermal fenton reaction	1 g L−1 certain types of MPs (UHMWPE, LDPE, HDPE, PS, PVC, PP, or PET) dispersed in 150 mL of ultrapure water	95.9% weight loss of MPs in 4–16 h	[149]
Functionalized carbon nanosprings (Mn@NCNTs/PMS) degrade MPs	The magnetic nanohybrids were applied for peroxymonosulfate activation to generate highly oxidizing radicals to decompose MPs under hydrothermal conditions	Extracted from facial cleanser paste	The Mn@NCNTs/PMS system can realize 50 wt % of MPs removal by assisting with hydrolysis	[150]
ZnO nanorod photocatalysts	Photocatalytic degradation	Fragmented LDPE MPs residues	N/A	[151]