Photocatalytic Conversion of Waste Plastics into C₂ Fuels under Simulated Natural Environment Conditions

Abstract

Reported here is the first highly selective conversion of various waste plastics into C2 fuels under simulated natural environment conditions by a sequential photoinduced C−C cleavage and coupling pathway, where single‐use bags, disposable food containers, food wrap films, and their main components of polyethylene, polypropylene, and polyvinyl chloride can be photocatalytically transformed into CH3COOH without using sacrificial agents. As an example, polyethylene is photodegraded 100 % into CO2 within 40 h by single‐unit‐cell thick Nb2O5 layers, while the produced CO2 is further photoreduced to CH3COOH. Various methods and experiments disclose that O2 and .OH radicals trigger the oxidative C−C cleavage of polyethylene to form CO2, while other investigations show that the yielded CH3COOH stems from CO2 photoreduction by C−C coupling of .COOH intermediates. This two‐step plastic‐to‐fuel conversion may help to simultaneously address the white pollution crisis and harvest highly valuable multicarbon fuels in natural environments.

Synthesis of CdS/MoS2 Nanooctahedrons Heterostructure with a Tight Interface for Enhanced Photocatalytic H2 Evolution and Biomass Upgrading

“…Solar‐driven biomass upgrading and their reforming to H 2 offer a straightforward and low‐energy way to convert wastes into renewable fuels, which efficiently utilize the photo‐generated holes and simultaneously boost photocatalytic H 2 production. [ 19,20 ] For instance, Reisner and co‐workers reported the photoreforming of cellulose, lignin, and hemicellulose to H 2 using semiconducting CdS quantum dots as photocatalysts in alkaline aqueous solution. During the photoreforming process, the photocatalyst provided electrons for the reduction of protons to produce H 2 through biomass oxidation, and achieved the high activity of H 2 generation without CdS photocorrosion.…”

In-Situ Synthesis of TiO2@GO Nanosheets for Polymers Degradation in a Natural Environment

“…Besides, in the recycle degradation of P2, the activity of TiO 2 @GO remained about 88% after three times recycle degradations in Figure 6, revealing its high photocatalytic stability. In this study, it was strongly demonstrated the polymers underwent a photoox tive C-C bond cleavage process to get the CO2, H2O, and ROX with TiO2@GO as photocatalyst in a natural environment [23][24][25]. The photocatalytic propertie TiO2@GO were well-researched, as shown in Scheme 3 [26].…”

“…The accumulated h were oxidative reaction with the H2O to produce •OH, and simultaneously the elec and H + was also interacted with the O2 to bring the H2O2, leading to achieving the radation of polymers. In this study, it was strongly demonstrated the polymers underwent a photooxidative C-C bond cleavage process to get the CO 2 , H 2 O, and RO X with TiO 2 @GO as the photocatalyst in a natural environment [23][24][25]. The photocatalytic properties of TiO 2 @GO were well-researched, as shown in Scheme 3 [26].…”

“…In this study, it was strongly demonstrated the polymers underwent a photooxidative C–C bond cleavage process to get the CO 2 , H 2 O, and RO X with TiO 2 @GO as the photocatalyst in a natural environment [ 23 , 24 , 25 ]. The photocatalytic properties of TiO 2 @GO were well-researched, as shown in Scheme 3 [ 26 ].…”

Recent Advancements in Photocatalytic Valorization of Plastic Waste to Chemicals and Fuels

“…Besides one-step conversion, Xie, and co-workers (Jiao et al, 2020) recently have reported a sequential photoinduced C-C cleavage under atmosphere and C-C bond coupling in the absence of oxygen, which for the first time realizes highly selective conversion of various waste plastic into C 2 fuels under simulated natural environment (room temperature, pure water, and simulated one-sun irradiation; Supplementary Figure 6A). In the research, single-unit-cell thick Nb 2 O 5 layers (2.96 nm) is prepared from niobic acid atomic layer precursor as catalyst (Supplementary Figure 6B), due to its high redox potentials, valence band maximum at + 2.5 V vs. NHE and the conduction band minimum at 0.9 V vs. NHE at pH 7, which is conducive for maximal exposure of active site and thus promoting the light conversion performance.…”