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A recent study published in the journal Synlett discusses a new method for the chemical recycling of plastic waste, specifically polystyrene. The study focuses on the use of an iron-based catalyst to degrade polystyrene into benzoic acid under mild conditions. The research explores different catalysts and solvent effects, and demonstrates the potential for plastic degradation using atmospheric air. This study provides valuable insights into the development of more efficient and sustainable methods for plastic recycling, offering a potential solution to the significant environmental problem of plastic waste. Additionally, another article presents a novel approach for the selective degradation of polystyrene products using a photoinduced iron catalyst. The study examines various polystyrene waste materials and finds that the approach effectively converts them into valuable chemicals such as formic acid and benzoic acid. The research provides insights into the potential for chemical upcycling of common polystyrene products and waste, offering a promising avenue for reducing plastic waste. [Extracted from the article]

Dimensional control of nano-photocatalysts enables the enhancement of catalytic activity through optimization of electronic structures. In this study, we take Znln 2 S 4 as an example to demonstrate the influence of dimensional structure on photocatalytic reactions. Firstly, we successfully prepared three different dimensional structures of Znln 2 S 4 (including 1D, 2D, and 3D Znln 2 S 4) using a surfactant-assisted synthesis method. In photocatalytic experiments, we found that Znln 2 S 4 exhibits dimension-dependent catalytic performance in both photocatalytic hydrogen production and photodegradation of dye solutions. Among them, 2D ZnIn 2 S 4 demonstrates highest photocatalytic performance. The hydrogen evolution rate of 2D ZnIn 2 S 4 reached 0.69 mmol g−1 h−1, which was 3.29 and 1.17 times higher than 1D ZnIn 2 S 4 and 3D ZnIn 2 S 4 , respectively. In addition, the degradation rate of Rodamine B (RhB) by 2D ZnIn 2 S 4 reached 92.3 % within 30 min, significantly higher than that of 1D ZnIn 2 S 4 (70.3 %) and 3D ZnIn 2 S 4 (86.3 %). The origin for high activity of 2D ZnIn 2 S 4 was investigated by multiple perspectives including light absorption range, charge separation efficiency, band structure, and specific surface area. The results revealed that the high activity of 2D ZnIn 2 S 4 may mainly originate from its dimension-controlled high charge separation efficiency. [Display omitted] • Dimension control of ZnIn 2 S 4 is realized by surfactant-assisted synthesis. • Dimension-dependent photocatalytic activity of Znln 2 S 4 is demonstrated. • The origin of dimension-dependent activity is uncovered in detail. [ABSTRACT FROM AUTHOR]

Phase engineering is an emerging strategy for tuning the electronic states and catalytic functions of nanomaterials. Great interest has recently been captured by phase-engineered photocatalysts, including the unconventional phase, amorphous phase, and heterophase. Phase engineering of photocatalytic materials (including semiconductors and cocatalysts) can effectively affect the light absorption range, charge separation efficiency, or surface redox reactivity, resulting in different catalytic behavior. The applications for phase-engineered photocatalysts are widely reported, for example, hydrogen evolution, oxygen evolution, CO2 reduction, and organic pollutant removal. This review will firstly provide a critical insight into the classification of phase engineering for photocatalysis. Then, the state-of-the-art development of phase engineering toward photocatalytic reactions will be presented, focusing on the synthesis and characterization methodologies for unique phase structure and the correlation between phase structure and photocatalytic performance. Finally, personal understanding of the current opportunities and challenges of phase engineering for photocatalysis will also be provided. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: While polystyrene is widely used in daily life as a synthetic plastic, the subsequently selective degradation is still very challenging and highly required. Herein, we disclose a highly practical and selective reaction for the catalytically efficient oxidation of alkyl aromatics (including 1°, 2°, and 3° alkyl aromatics) to carboxylic acids. While dioxygen was used as the sole terminal oxidant, this protocol was catalyzed by the inexpensive and readily available ferric compound (FeCl3) with irradiation of visible light (blue LEDs) under only 1 atmosphere of O2 at room temperature. This system could further facilitate the selective degradation of polystyrene to benzoic acid, providing an important and practical tool to generate high‐value chemical from abundant polystyrene wastes. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: While polystyrene is widely used in daily life as a synthetic plastic, the subsequently selective degradation is still very challenging and highly required. Herein, we disclose a highly practical and selective reaction for the catalytically efficient oxidation of alkyl aromatics (including 1°, 2°, and 3° alkyl aromatics) to carboxylic acids. While dioxygen was used as the sole terminal oxidant, this protocol was catalyzed by the inexpensive and readily available ferric compound (FeCl3) with irradiation of visible light (blue LEDs) under only 1 atmosphere of O2 at room temperature. This system could further facilitate the selective degradation of polystyrene to benzoic acid, providing an important and practical tool to generate high‐value chemical from abundant polystyrene wastes. [ABSTRACT FROM AUTHOR]

The integration of peroxymonosulfate (PMS) activation and photocatalysis is an effective advanced oxidation technology for the degradation of water pollutants. In this study, iron phthalocyanine (FePc) is successfully loaded onto O-doped porous carbon nitride (OCN) forming a catalyst working in photo-assisted PMS activation. OCN is a metal-free light absorber with strong visible light absorption, while FePc could serve as a photosensitizer and PMS activator. At the same time, the construction of FePc/OCN heterojunction can form the strong internal electric field for charge migration between FePc and OCN. As a result, complete tetracycline (TC) removal within 30 min can be achieved over optimal FePc/OCN catalyst in the presence of light and PMS. Systematic controlled experiments were also carried out to reveal the effect of pH, anion, and aqueous matrix. Cyclic stability test and Fe leaching experiments indicate that the synthesized FePc/OCN is relatively stable and shows the potential in practical application. Furthermore, a comprehensive investigation was conducted on the reactive species generated during the reaction process as well as the degradation pathways of the target pollutants. This work aims to provide new insights into the design of efficient catalysts for photo-assisted PMS activation. [Display omitted] • FePc/OCN is reported for photo-assisted PMS activation reaction. • Nearly 100% TC can be decomposed using FePc/OCN in the presence of PMS and light. • The origin for highly efficient performance is explored systematically. [ABSTRACT FROM AUTHOR]

An inverse emulsion radical reaction was adopted to prepare poly(vinyl alcohol) (PVA)-based microgels that contained titanium oxide (TiO2) or TiO2/Fe3O4, and the obtained microgels were applied to catalyze the degradation of methyl orange. First, well-defined PVA was used to synthesize a PVA-based macromonomer (PVAM) that contained carbon-carbon double bonds of tunable contents. Then, the composite microgels were prepared via the crosslinking reaction between PVAM and acrylic acid in the presence of TiO2 or TiO2/Fe3O4. Thermogravimetric analysis (TGA) and scanning electron microscope observation confirmed that the inorganic nanoparticles were well encapsulated within the microgels. TGA results showed that the loading efficiency of TiO2 was able to be controlled by varying the structure of PVAM. It was found that the microgels can efficiently catalyze the degradation of methyl orange. Moreover, the composite microgels possessed controllable and returnable catalysis ability. In addition, the separation of the composite microgels from aqueous solution could be quite easily accomplished by incorporating magnetic particles. POLYM. COMPOS., 38:132-137, 2017. © 2015 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Phase engineering plays a critical role in enhancing photocatalytic performance of metal oxides. Herein, we demonstrate the phase-selective synthesis of MoO 3 (hexagonal h-MoO 3 , orthorhombic α-MoO 3 , and their junction h/α-MoO 3) through controlled phase transitions by adjusting annealing conditions. As evidenced with photocatalytic hydrogen evolution reaction, h/α-MoO 3 (14.20 μmol/h) phase junction shows superior performance to either h-MoO 3 (9.62 μmol/h) or α-MoO 3 (11.31 μmol/h), with a hydrogen yield of 47.6% and 25.6% greater than that of h-MoO 3 and α-MoO 3 (Pt as cocatalyst), respectively. A systematic study of the chemical structure characterizations, photochemical tests, band structure analysis, and photocatalytic activity evaluation reveal that, the enhancement is attributed to the strong built-in electric field in the h/α-MoO 3 phase junction, which effectively facilitates charge separation. Our findings introduce a novel strategy for improving photocatalytic performance using phase engineering. [Display omitted] • MoO 3 with different phase structures can be synthesized by controllable phase transition for h-MoO 3 to α-MoO 3. • Heterophase h/α-MoO 3 demonstrates enhanced photocatalytic hydrogen production efficiency h-MoO 3 and α-MoO 3. • Phase junction induced built-in electric field can promote charge separation toward improved photocatalysis. [ABSTRACT FROM AUTHOR]

Comprehensive Summary It is urgent to recycle polyethylene terephthalate (PET) effectively, since it is the most consumed synthetic polyester and its improper disposal has caused significant environmental pollution. The existing chemical recycling methods highly rely on the nucleophilic substitutions and hydrogenative depolymerizations, which typically require the use of excess of nucleophiles, excess strong acids or bases, expensive metal catalysts, and explosive gas atmosphere. Here, we demonstrate a mild and efficient protocol for oxidative depolymerization of PET to terephthalic acid using only an O2 balloon. Terephthalic acid can be recycled from PET‐containing materials including a series of plastic products in daily life. The employing of relatively low loading of iron complex, the most earth‐abundant transition metal, as the catalyst and the preliminary results on the large‐scale reaction using 38 g of PET waste demonstrate the practical feasibility of this degradation method. This method can be also applicable for selective degradation of PET from mixed plastics. This work represents a rare example of a selective oxidative depolymerization and demonstrates the great potentials of such a concept in polyester recycling. [ABSTRACT FROM AUTHOR]

We report here the role of exposed facet in CdS nanostructures for photocatalytic hydrogen evolution, and the effects to surface reaction and interfacial charge transfer. [Display omitted] • Shape-controlled synthesis of CdS to expose different facets is realized. • Facet-dependent photocatalytic hydrogen evolution performance is demonstrated. • The role of facet-engineered surface and interface is uncovered. Crystal facet of materials is an important parameter that affects the catalytic properties of photocatalysts. In this study, taking CdS as a prototype, we demonstrate the different role of facet as surface active site and interfacial charge migration channel. CdS nanorods exposed with {1 0 0} facet and CdS nanosheets exposed with {0 0 1} facet can be synthesized via simple wet chemical methods. In photocatalytic reaction, experimental results demonstrate that pristine CdS nanorods show higher hydrogen evolution rate (16.99 μmol/h) than that of pristine CdS nanosheets (4.97 μmol/h). As a contrast, when integrating with Pt cocatalyst forming Pt-CdS hybrids, the loading of Pt can improve the hydrogen evolution rate of CdS nanorods by 9.99-folds, significantly lower than CdS nanosheets (26.41-folds). In the case of using pristine CdS as catalysts, {1 0 0} facet is more beneficial for proton adsorption compared to {0 0 1} facet, leading to higher performance of CdS nanorods exposed with {1 0 0} facet as surface reaction sites. As for Pt/CdS catalysts, photogenerated electrons can more effectively transfer across the CdS {0 0 1}-Pt interface than that of CdS {1 0 0}-Pt interface, resulting in higher enhancement factors of CdS nanosheets after loading of Pt cocatalysts. These results may provide ideas for designing photocatalysts based on facet engineering. [ABSTRACT FROM AUTHOR]