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Abstract Artificial photosynthesis is a promising strategy for efficient hydrogen peroxide production, but the poor directional charge transfer from bulk to active sites restricts the overall photocatalytic efficiency. To address this, a new process of dipole field-driven spontaneous polarization in nitrogen-rich triazole-based carbon nitride (C3N5) to harness photogenerated charge kinetics for hydrogen peroxide production is constructed. Here, C3N5 achieves a hydrogen peroxide photosynthesis rate of 3809.5 µmol g−1 h−1 and a 2e− transfer selectivity of 92% under simulated sunlight and ultrasonic forces. This high performance is attributed to the introduction of rich nitrogen active sites of the triazole ring in C3N5, which brings a dipole field. This dipole field induces a spontaneous polarization field to accelerate a rapid directional electron transfer process to nitrogen active sites and therefore induces Pauling-type adsorption of oxygen through an indirect 2e− transfer pathway to form hydrogen peroxide. This innovative concept using a dipole field to harness the migration and transport of photogenerated carriers provides a new route to improve photosynthesis efficiency via structural engineering.

Advanced oxidation processes (AOPs) utilizing persulfate (PS) offer great potential for wastewater treatment. Yet, the dependency on energy and chemical-intensive activation techniques, such as ultraviolet radiation and transition metal ions, constrains their widespread adoption. Recognizing this limitation, researchers are turning towards the piezoelectric effect—a novel, energy-efficient method for PS activation that capitalizes on the innate piezoelectric characteristics of materials. Intriguingly, this method taps into weak renewable mechanical forces omnipresent in nature, ranging from wind, tides, water flow, sound, and atmospheric forces. In this perspective, we delve into the burgeoning realm of piezoelectric/PS-AOPs, elucidating its fundamental principles, the refinement of piezoelectric materials, potential mechanical force sources, and pertinent application contexts. This emerging technology harbors significant potential as a pivotal element in wastewater pretreatment and may spearhead innovations in future water pollution control engineering.

Operando monitoring of highly localized and rapid temperature changes during photo-involved catalysis reactions at liquid-solid interfaces via narrow bandwidth fiber-optic spectral combs.

An alternative approach to defect-trapped Pt single-sites on a semiconductor is reported. Here, protruding Pt sites inhibit charge recombination and cause a tip effect which enhances H2 evolution yield rates with minimal co-catalyst loading.

The efficient activation and utilization of peroxymonosulfate (PMS) in PMS-based advanced oxidation processes is a high-priority target for the removal of organic contaminants. This work introduces a water vortex-driven piezoelectric effect from few-odd-layered MoS2 into the PMS activation to remove benzotriazole (BTR) and other organic contaminants from the water. Approximately 91.1% of BTR can be removed by the MoS2 piezo-activated PMS process with a reaction rate constant of 0.428 min−1, which is 2.09 times faster than the sum of the individual MoS2, water vortex, and piezocatalysis rates. Meanwhile, the PMS utilization efficiency reached 0.0147 in the water vortex-driven piezo-activation system, which is 3.97 times that of the sum from the vortex/PMS and MoS2/PMS systems. These results demonstrate that the presence of MoS2 under a water vortex can trigger a piezoelectric potential and generate abundant free electrons to activate PMS to generate various active species for degradation of organic contaminants.

Fluorinated liquid crystal monomers (LCMs) are begun to emerge as new persistent organic pollutants. Herein, the structure-reactivity relationships of fluorinated LCMs 1,2,3-trifluoro-5-[3-(3-propylcyclohexyl)cyclohexyl]benzene (TPrCB), 1,2-difluoro-4-[trans-4-(trans-4-propylcyclohexyl)cyclohexyl]benzene (DPrCB), 4-[(trans,trans)-4'-(3-Buten-1-yl)[1,1′-bicyclohexyl]-4-yl]-1,2-difluoro-benzene (BBDB) and 1-[4-(4-ethylcyclohexyl)cyclohexyl]-4(trifluoromethoxy)benzene (ECTB) subject to photocatalysis-generated oxidation species were investigated. The degradation rate constant of BBDB was 3.0, 2.6, and 6.8 times higher than DPrCB, TPrCB and ECTB, respectively. The results reveal that BBDB, DPrCB and TPrCB had mainly negative electrostatic potential (ESP) regions which were vulnerable to electrophilic attack by h+, •OH and •O2−, while ECTB was composed of mainly positive ESP regions which were vulnerable to nucleophilic attack by •OH and •O2−. The detoxification processes of BBDB, DPrCB and TPrCB included carbon bond cleavage and benzene ring opening. However, the methoxy group of ECTB reduced the nucleophilic reactivity on the benzene ring, leading to slower detoxification efficiency. These findings may help to develop LCMs treatment technologies based on structure-reactivity relationships.

Photoinitiators (PIs) are indispensable additives in photopolymerization. PI-containing consumables, such as adhesives, coatings, UV-cured inks and light-sensitive materials, are widely used in various electronic products. Nevertheless, there is no information concerning the identification of PIs as emerging contaminants from e-waste recycling. In this study, 25 PIs, including 9 benzophenones (BZPs), 8 amine coinitiators (ACIs), 4 thioxanthones (TXs) and 4 phosphine oxides (POs), were analyzed in indoor dust from typical e-waste recycling facilities and adjacent rural communities, as well as from control urban communities. All 25 target PIs were detected in e-waste dust, while only 17 and 15 of the 25 target PIs were detected in local home dust and urban home dust, respectively. The PIs detected in all dust samples were dominated by BZPs and POs, followed by ACIs and TXs. Most PIs exhibited significantly higher levels in e-waste dust than local or urban home dust. The influence of PI contamination on the local household environment by dust diffusion and transport from near e-waste recycling facilities may be lower due to the low volatility of most PIs. Characteristic composition profiles of PIs for indoor dust from the e-waste recycling area were identified and compared to those from the control area. Significant correlations were found among almost all the frequently detected PIs in the e-waste dust, indicating their similar application in electronic products and common emission from e-waste recycling. The estimated daily intakes of PIs via dust ingestion for the e-waste dismantling workers, as determined by using Monte Carlo analysis, were several times higher than those for the local adult residents and the general urban adult residents, which should be an emerging concern. To the best of our knowledge, this is the first report showing that e-waste dismantling/recycling activities lead to largely common releases of a wide range of multiple classes of PIs. Keywords: Photoinitiators, E-waste recycling facility, Indoor dust, Human exposure, Estimated daily intake

Chlorinated paraffins (CPs) are now attracting special concerns worldwide as one type of new persistent toxic substances as classified by the Stockholm Convention. CPs are extensively applied in household goods and indoor decoration materials, but information on their occurrence and exposure risk in such environments is still very scarce. In this study, the current concentrations, particle size distributions, and inhalation exposure characteristics and risk of CPs were investigated in regard to indoor air particulate matter. Both short chain (SCCPs) and medium chain CPs (MCCPs) were determined in all size-fractioned particle samples with a range of 6.20–17.8 and 5.98–40.5 ng m−3, respectively. MCCPs were more abundant than SCCPs. Size distributions revealed that individual homologs, SCCPs, and MCCPs exhibited a similar unimodal distribution peaking in the fine particles with a diameter of 0.56–1.0 μm. The relative abundance of longer-chain or more heavily chlorinated homologs tend to gradually increase with particle size shift from coarse to fine mode. Vapor pressure may be a critical factor governing the size-dependent distribution of CPs. Deposition of particulate CPs in the human respiratory tract is also size-dependent. The contributions of fine particles to the regional depositions of CPs in the human respiratory tract increase with increasing carbon chain length or chlorine content. Based on the size-dependent distributions of CPs, inhalation exposure assessment from the ICRP model indicated no significant health risk due to CPs in current indoor environments.

Magnetite (Fe3O4) is one of the widely used materials as a catalyst in the photo‐Fenton process for the oxidation of dyes. We report about the electrochemical synthesis of the superparamagnetic Fe3O4 nanoparticles. The structure, morphology, chemical composition, and chemical state of the catalyst were characterized. The synthesized samples of superparamagnetic Fe3O4 nanoparticles were characterized using scanning electron microscopy, X‐ray diffraction spectroscopy (XRD), Raman shift spectroscopy, and vibrating magnetometer (VSM). The diffraction peaks and Raman shift spectra confirm the formation of Fe3O4. Superparamagnetic Fe3O4 nanoparticles were used as a catalyst for the oxidation of Rhodamine B (RhB) in a photo‐Fenton‐like process. The effect of operating parameters, including H2O2 concentration, catalyst concentration, and RhB concentration, on the RhB decomposition efficiency was investigated. The rate of color removal was 85 % after 12 minutes at RhB concentration of 2 mg/L, H2O2 concentration of 0.18 mM, and Fe3O4 concentration of 0.2 g/L. In addition, electrochemically synthesized superparamagnetic Fe3O4 nanoparticles showed that the catalyst activity decreased by only 7 % during recycling experiments, indicating long‐term stability of the sample. [ABSTRACT FROM AUTHOR]