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Perovskite light-emitting diodes (PeLEDs) are rising techniques that have attracted worldwide attention, and the community is increasingly considering vapor-phase deposition (VPD) as a promising route to realize reliable perovskite displays. Transmission electron microscopy (TEM) has been extensively applied to characterize the structural details of perovskites and related devices. However, under conventional imaging conditions, the high-energy electron beam is sufficient to cause collapse of the original crystal structure and the electron radiation effect on perovskites prepared by VPD has not been systematically studied. In this study, the damage and recovery processes of vacuum-deposited perovskite nanocrystalline structures are systematically studied by comprehensive transmission electron microscopy (TEM) techniques. It is observed that with prolonged electron beam irradiation, the CsPbBr3nanocrystals surrounding the irradiation zone are gradually damaged, generating Pb nanoparticles, whereas the crystal structure within the irradiated region is not damaged. Further theoretical analysis reveals that a high-energy electric field is formed at the edge of the irradiation zone due to electron beam irradiation, which would lead to Br ion migration to the irradiation center and the breakdown of the CsPbBr3nanocrystalline structure at the periphery regions. When the electron beam is shifted to the periphery region, the Pb nanoparticles gradually disappear with the regrowth of CsPbBr3nanocrystals, which indicates that Br ions migrate back to the newly positively charged irradiation zone. The mechanism of the reversible transformation process is highly related to the electron beam-induced electric field, which would facilitate a deeper understanding of the electron beam irradiation effect on perovskite materials and help understand and enhance the stability of perovskites in devices.

The photochemically generated oxidative organic radicals (POORs) in dissolved black carbon (DBC) was investigated and compared with that in dissolved organic matter (DOM). POORs generated in DBC solutions exhibited higher one-electron reduction potential values (1.38–1.56 V) than those in DOM solutions (1.22–1.38 V). We found that the photogeneration of POORs from DBC is enhanced with dissolved oxygen (DO) increasing, while the inhibition of POORs is observed in reference to DOM solution. The behavior of the one-electron reducing species (DBC•–/DOM•–) was employed to explain this phenomenon. The experimental results revealed that the DO concentration had a greater effect on DBC•–than on DOM•–. Low DO levels led to a substantial increase in the steady-state concentration of DBC•–, which quenched the POORs via back-electron reactions. Moreover, the contribution of POORs to the degradation of 19 emerging organic contaminants (EOCs) in sunlight-exposed DBC and DOM solutions was estimated. The findings indicate that POORs play an important role in the photodegradation of EOCs previously known to react with triplets, especially in DBC solutions. Compared to DOM solutions, POOR exhibits a lower but considerable contribution to EOC attenuation. This study enhances the understanding of pollutant fate in aquatic environments by highlighting the role of DBC in photochemical pollutant degradation and providing insights into pollutant transformation mechanisms involving POORs.

Among the increasingly popular miniature and flexible smart electronics, two-dimensional materials show great potential in the development of flexible electronics owing to their layered structures and outstanding electrical properties. MXenes have attracted much attention in flexible electronics owing to their excellent hydrophilicity and metallic conductivity. However, their limited interlayer spacing and tendency for self-stacking lead to limited changes in electron channels under external pressure, making it difficult to exploit their excellent surface metal conductivity. We propose a strategy for rapid gas foaming to construct interlayer tunable MXene aerogels. MXene aerogels with rich interlayer network structures generate maximized electron channels under pressure, facilitating the effective utilization of the surface metal properties of MXene; this forms a self-healable flexible pressure sensor with excellent sensing properties such as high sensitivity (1,799.5 kPa–1), fast response time (11 ms), and good cycling stability (>25,000 cycles). This pressure sensor has applications in human body detection, human–computer interaction, self-healing, remote monitoring, and pressure distribution identification. The maximized electron channel design provides a simple, efficient, and scalable method to effectively exploit the excellent surface metal conduction of 2D materials.

Sulfate radical (SO4•–)-mediated advanced oxidation processes via peroxymonosulfate (PMS) activation have been extensively investigated. However, the phototransformation of PMS in sunlit dissolved organic matter (DOM) solution has not been previously examined. For the first time, the photosensitized transformation of PMS in DOM-enriched solutions under simulated solar irradiation was observed. The generation of reactive species, including 1O2, SO4•–, and •OH, was confirmed by electron paramagnetic resonance and quantified by chemical probes. SO4•–was the primary reactive species generated via the reaction of excited triplet DOM (3DOM*) with PMS. 3DOM* acted as a reactive reductant and was quickly oxidized by PMS, with an estimated reaction rate constant of (4.09 ± 0.21) × 108M–1s–1. Compared to 3DOM*, one-electron-reducing DOM (DOM•–) was a minor contributor to the photosensitized transformation of PMS, and the contribution of DOM•–relied on the phenolic constituents. In addition, a series of different types of DOM, including terrestrial DOM, autochthonous DOM, and effluent organic matter and its fractions, were employed to examine the photosensitized transformation kinetics of PMS. Overall, the photosensitized transformation of PMS by irradiated DOM could be a useful and economical approach to generate SO4•–under environmentally relevant conditions.

Hydroxyl radicals (•OH) are important reactive species that are photochemically generated through solar irradiation of chromophoric dissolved organic matter (CDOM) in surface waters. However, the spatial distribution within the complex three-dimensional structure of CDOM has not been examined. In this study, we used a series of hydrophobic chlorinated paraffins as chemical probes to elucidate the microheterogeneous distribution of •OH in illuminated CDOM solutions. The steady-state concentration of •OH inside the CDOM microphase is 210 ± 31-fold higher than the concentration in the aqueous phase. Our results suggest that the most photochemically generated •OH are confined into the CDOM microphase. Thus, illuminated CDOM behaves as a natural microreactor for •OH-based oxidations. By including intra-CDOM •OH, the quantum yield of •OH for CDOM solutions was estimated to be 2.2 ± 0.5 × 10–3, which is 2 orders of magnitude greater than previously thought. The elevated concentrations of photogenerated •OH within the CDOM microphase may improve the understanding of hydrophobic pollutant degradation in aqueous environments. Moreover, our results also suggest that •OH oxidation may play more important roles in the phototransformation of CDOM than previously expected.

Field observations of daytime HONO source strengths have not been well explained by laboratory measurements and model predictions up until now. More efforts are urgently needed to fill the knowledge gaps concerning how environmental factors, especially relative humidity (RH), affect particulate nitrate photolysis. In this work, two critical attributes for atmospheric particles, i.e., phase state and bulk-phase acidity, both influenced by ambient RH, were focused to illuminate the key regulators for reactive nitrogen production from typical internally mixed systems, i.e., NaNO3and dicarboxylic acid (DCA) mixtures. The dissolution of only few oxalic acid (OA) crystals resulted in a remarkable 50-fold increase in HONO production compared to pure nitrate photolysis at 85% RH. Furthermore, the HONO production rates (PHONO) increased by about 1 order of magnitude as RH rose from <5% to 95%, initially exhibiting an almost linear dependence on the amount of surface absorbed water and subsequently showing a substantial increase in PHONOonce nitrate deliquescence occurred at approximately 75% RH. NaNO3/malonic acid (MA) and NaNO3/succinic acid (SA) mixtures exhibited similar phase state effects on the photochemical HONO production. These results offer a new perspective on how aerosol physicochemical properties influence particulate nitrate photolysis in the atmosphere.

Advanced oxidation processes (AOPs), such as hydroxyl radical (HO•)- and sulfate radical (SO4•–)-mediated oxidation, are attractive technologies used in water and wastewater treatments. To evaluate the treatment efficiencies of AOPs, monitoring the primary radicals (HO•and SO4•–) as well as the secondary radicals generated from the reaction of HO•/SO4•–with water matrices is necessary. Therefore, we developed a novel chemical probe method to examine five key radicals simultaneously, including HO•, SO4•–, Cl•, Cl2•–, and CO3•–. Five probes, including nitrobenzene, para-chlorobenzoic acid, benzoic acid, 2,4,6-trimethylbenzoic acid, and 2,4,6-trimethylphenol, were selected in this study. Their bimolecular reaction rate constants with diverse radicals were first calibrated under the same conditions to minimize systematic errors. Three typical AOPs (UV/H2O2, UV/S2O82–, and UV/HSO5–) were tested to obtain the radical steady-state concentrations. The effects of dissolved organic matter, Br–, and the probe concentration were inspected. Our results suggest that the five-probe method can accurately measure radicals in the HO•- and SO4•–-mediated AOPs when the concentration of Br–and DOM are less than 4.0 μM and 15 mgCL–1, respectively. Overall, the five-probe method is a practical and easily accessible method to determine multiple radicals simultaneously.

Nicotine is a highly toxic tobacco alkaloid that is ubiquitous in wastewater effluent. For the first time, we report the identification of the products and the pathways for the photodegradation of nicotine in an effluent matrix under simulated solar irradiation. Nicotine was found to be degraded by triplet-state organic matter (3OM*), thus indicating that electron transfer is a preferred reaction mechanism. Using the multivariate statistical strategies orthogonal projection to latent structures discriminant analysis (OPLS-DA) and hierarchical clustering, 49 potential transformation products (TPs) of nicotine were successfully extracted from the water matrix via high-resolution ultrahigh-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UHPLC–QTOF-MS). Overall, 30 TPs, including 4 groups of nonseparated isomeric photo TPs, were identified with various levels of confidence based on the tandem mass spectrometry information on standard compounds and the isotope-labeling method (using rac-nicotine-2′,3′,3′-D3, rac-nicotine-13CD3, and rac-nicotine-D4) under air-saturated conditions. The pyrrolidine ring of nicotine was found to be the reactive site under sunlight irradiation. Pseudooxynicotine was the main primary TP from nicotine, with a maximum transformation ratio of 64%. Nicotinic acid, cotinine, 3′-hydroxycotinine, and myosmine were the final stable TPs after 72 h of solar irradiation, with yields of 13%, 3%, 5%, and 5%, respectively.

Although it is known that the solar irradiation of chromophoric dissolved organic matter (CDOM) solutions generates H2O2, whether or not organic hydroperoxides (ROOHs) are photochemically formed remains unclear. This study employs high-performance liquid chromatography with the postcolumn enzymatic derivatization method to examine whether ROOHs can be formed in CDOM solutions under simulated solar irradiation. Methylhydroperoxide (MHP) is the only identified ROOH under our experimental conditions, and the quantum yields of MHP (ΦMHP) vary from (1.09 ± 0.09) × 10–6to (4.95 ± 0.11) × 10–6in the tested CDOM solutions, including four reference natural organic matters and two effluent organic matters. The quantum yields of H2O2(ΦH2O2) are simultaneously measured, and the ratios of ΦH2O2to ΦMHPrange from 147 to 676. The formation of MHP is highly related to the presence of superoxide radical ions (O2•–) and methyl radicals (CH3•); therefore, a photoformation mechanism of MHP has been proposed. The photochemically generated CH3•reacts with O2to yield CH3OO•. Subsequently, CH3OO•is reduced to MHP by O2•–. Our results also suggest that the yield of CH3•to MHP under air-saturated conditions is 52% and increases to 98% under oxygen-saturated conditions. The decays of MHP and H2O2are very similar in terms of photodegradation, hydrolysis, Fenton, and photo-Fenton reactions. This study can be useful to understand the photochemical formation of organic peroxides in surface waters.

This paper examines the need for inland ports in Sri Lanka. A hybrid approach comprising both quantitative and qualitative methods was used in here using the data collected through primary surveys and published sources. It concludes that the inland ports of Sri Lanka are needed not very much as incentive to freight management process but as a solution to capacity-related issues on the roads. Findings further show that inland ports could offer relief to heavily congested roads of the city of Colombo and ushering substantial savings to the economy.

Cylindrospermopsin (CYN) is one of the most important cyanobacterial toxins frequently found in surface waters. We reported the detailed kinetics and pathways for the reaction of CYN with carbonate radicals (CO3•–). The rate constants of neutral and deprotonated CYN with CO3•–were found to be (1.2 ± 0.7) × 107M–1s–1and (3.0 ± 0.4) × 108M–1s–1, respectively. The transformation products for the oxidation of CYN by CO3•–were identified by high-resolution mass spectrometry, illustrating that the guanidine and bridged hydroxyl portions were the primary moieties attacked by CO3•–. Thus, three transformation pathways, including cleavage of the hydroxymethyluracil moiety, hydroxylation, and oxidation of the bridged hydroxyl group, are proposed for the CO3•–oxidation of CYN. Moreover, this study reported that dissolved organic matter (DOM) reduced the transformation rate of CYN by inhibiting the transformation of oxidation intermediates. Finally, the role of CO3•–in CYN degradation was estimated in both sunlit surface waters and advanced oxidation processes (AOPs), demonstrating that CO3•–played an important role in CYN attenuation under nonacidic environmentally relevant conditions. The kinetic parameters and product information obtained in this study will be of considerable interest for the application of AOPs and predicting the environmental fate of CYN.

Dissolved black carbon (DBC) is an important component of dissolved organic matter pool; however, its photochemical properties are not fully understood. In this study, we determined the excited triplet-state quantum yields of DBC (3DBC*) and 1O2quantum yields (Φ1O2) of six diverse DBCs using sorbic alcohol, 2,4,6-trimethylphenol (TMP), and furfuryl alcohol and compared the results with quantum yields of reference natural organic matters (NOMs). The average Φ1O2of six DBCs (4.2 ± 1.5%) was greater than that of terrestrial NOM (2.4 ± 0.3%) and comparable to autochthonous NOM (5.3 ± 0.2%). Using TMP as a probe for oxidizing triplets, DBC presented significantly higher apparent quantum yield coefficients for degrading TMP (fTMP) than the reference NOM, reflecting that the fTMPvalues of low-energy 3DBC* were approximately 12-fold greater than those of low-energy 3NOM*. The differences in the fTMPand Φ1O2trends among the DBCs indicated that the 3DBC* responsible for these reactions may be from different sources. In addition, DBC was much more effective than NOM, on a carbon-normalized basis, during photodegradation of pharmaceutically active compounds. This result confirms that the presence of DBC can accelerate the photodegradation of contaminants that are susceptible to one-electron oxidation by triplets.

The photochemical formation and decay rates of superoxide radical ions (O2•–) in irradiated dissolved organic matter (DOM) solutions were directly determined by the chemiluminescent method. Under irradiation, uncatalyzed and catalyzed O2•–dismutation account for ∼25% of the total O2•–degradation in air-saturated DOM solutions. Light-induced O2•–loss, which does not produce H2O2, was observed. Both the O2•–photochemical formation and light-induced loss rates are positively correlated with the electron-donating capacities of the DOM, suggesting that phenolic moieties play a dual role in the photochemical behavior of O2•–. In air-saturated conditions, the O2•–quantum yields of 12 DOM solutions varied in a narrow range, from 1.8 to 3.3‰, and the average was (2.4 ± 0.5)‰. The quantum yield of O2•–nonlinearly increased with increasing dissolved oxygen concentration. Therefore, the quantum yield of one-electron reducing intermediates, the precursor of O2•–, was calculated as (5.0 ± 0.4)‰. High-energy triplets (3DOM*, ET> 200 kJ mol–1) and 1O2quenching experiments indicate that 3DOM* and 1O2play minor roles in O2•–production. These results are useful for predicting the photochemical formation and decay of O2•–in sunlit surface waters.

Photochemical transformation driven by sunlight is one of the most important natural processes for organic contaminant attenuation. In the current study, statistical analysis-assisted high-resolution mass spectrometry was employed to investigate the phototransformation of nontarget features in wastewater effluents under various radical quenching/enhancing conditions. A total of 9694 nontarget features were extracted from the effluents, including photoresistant features, photolabile features, and transformation products. 65% of the wastewater effluent features were photoresistant, and the photolabile features could be classified into five groups: direct photolysis group (group I), HO•-originated species-dominated group (group II), 3OM*-dominated group (group III), photochemically produced reactive intermediates combination-dominated group (group IV), and non-first-order degradation group (group V). The direct photolyzed features were observed to degrade significantly faster than the indirect photolyzed features. Moreover, group II dominated by HO•-originated species contributed 34% to the photolabile features. The reaction types that occurred in the phototransformation process were analyzed by linkage analysis. The results suggested that oxygen addition and dealkyl group reactions were the most common reaction types identified in the phototransformation process. Overall, high-resolution mass spectrometry coupled with statistical analysis was applied here to understand the photochemical behavior of the unknown features in wastewater effluents.

Graphical Abstract:

Excited triplet states of chromophoric dissolved organic matter (3CDOM*) are highly reactive species in sunlit surface waters and play a critical role in reactive oxygen species (ROS) formation and pollutant attenuation. In the present study, a series of chemical probes, including sorbic acid, sorbic alcohol, sorbic amine, trimethylphenol, and furfuryl alcohol, were employed to quantitatively determine 3CDOM* and 1O2in various organic matters. Using a high concentration of sorbic alcohol as high-energy triplet states quencher, 3CDOM* can be first distinguished as high-energy triplet states (>250 kJ mol–1) and low-energy triplet states (<250 kJ mol–1). The terrestrial-origin natural organic matter (NOM) was found to mainly consist of low-energy triplet states, while high-energy triplet states were predominant in autochthonous-origin NOM and effluent/wastewater organic matter (EfOM/WWOM). The 1O2quantum yields and electron transfer quantum yield coefficients (fTMP) generated from low-energy triplet states remained constant in all tested organic matters. External phenolic compound showed quenching effects on triplet-state formation and tended to have a higher quenching efficiency for aromatic ketone triplet states, which are the main high-energy triplet states. In comparison with terrestrial-origin NOM, autochthonous-origin NOM and EfOM/WWOM presented lower reaction rate constants for sorbic amines and higher reaction rate constants for sorbic acid, and these differences are likely due to dissimilar surface electric charge conditions. Understanding the triplet-state photochemistry of CDOM is essential for providing useful insights into their photochemical effects in aquatic systems.

MXenes have received extensive attention in the fields of energy storage and flexible electronics due to their excellent physicochemical properties. However, MXenes are prone to self-stacking, which would result in severely degraded performance of the electronic devices. Unlike the optimization of the structure-property relationship of MXene at specific scale in most reported studies, the current work is based on the multiscale design concept: MXene aerogels with abundant ion/electron channels are constructed through an efficient chemical oxidation and rapid gas foaming strategy. Nanoscale in-plane nanoporous MXenes can lead to increased ion channels and effectively shortened ion transport distances. Micron-scale MXene aerogels can provide abundant ionic active sites and maximized electron channels. The fabricated integrated self-healable flexible zinc-ion energy storage and pressure sensing system offers high areal specific capacitance of 576 mF cm−2, sufficient energy density of 156.8 uWh cm−2at a power density of 4200 uW cm−2, and ultra-high pressure sensitivity (1024.9 kPa−1), which has great potential in applications including self-healing and flexible wearable devices. The multiscale design concept achieves the maximization of ion/electron channels, realizing a thoughtful strategy for the optimization of flexible electronic devices.

Climate change and eutrophication are two environmental threats that can alter the structure of freshwater ecosystems and their service functions, but we know little about how ecosystem structure and function will evolve in future scenarios of climate warming. Therefore, we created different experimental climate scenarios, including present-day conditions, a 3.0 °C increase in mean temperature, and a “heatwaves” scenario (i.e., an increase in temperature variability) to assess the effects of climate change on phytoplankton communities under simultaneous stress from eutrophication and herbicides. We show that the effects of climate warming, particularly heatwaves, are associated with elevated cyanobacterial abundances and toxin production, driven by a change from mainly nontoxic to toxic Microcystisspp. The reason for higher cyanobacterial toxin concentrations is likely an increase in abundances because under the dual pressures of climate warming and eutrophication individual Microcystistoxin-producing ability decreased. Eutrophication and higher temperatures significantly increased the biomass of Microcystis, leading to an increase in the cyanobacterial toxin concentrations. In contrast, warming alone did not produce higher cyanobacterial abundances or cyanobacterial toxin concentrations likely due to the depletion of the available nutrient pool. Similarly, the herbicide glyphosate alone did not affect abundances of any phytoplankton taxa. In the case of nutrient enrichment, cyanobacterial toxin concentrations were much higher than under warming alone due to a strong boost in biomass of potential cyanobacterial toxin producers. From a broader perspective our study shows that in a future warmer climate, nutrient loading has to be reduced if toxic cyanobacterial dominance is to be controlled.

Chlorination is one of the most common disinfection methods for water treatments. Although the direct photolysis of free available chlorine (FAC) induced by solar irradiation has been extensively investigated, the photosensitized transformation of FAC caused by chromophoric dissolved organic matter (CDOM) has not previously been examined. Our results suggest that the photosensitized transformation of FAC can occur in sunlit CDOM-enriched solutions. Interestingly, the photosensitized decay of FAC can be fitted using a combined zero- and first-order kinetic model. The photogenerated O2•–from CDOM contributes to the zero-order kinetic component. The reductive triplet CDOM (3CDOM*) contributes to the pseudo-first-order decay kinetic component. The bimolecular reaction rate constants of the model triplet (3-methoxyacetophenone) with HOCl and OCl–were (3.6 ± 0.2) × 109and (2.7 ± 0.3) × 109M–1s–1, respectively. Under simulated solar irradiation, the quantum yield coefficient of the reductive 3CDOM* toward FAC attenuation (fFAC= 840 ± 40 M–1) was 13 times greater than that of the oxidative 3CDOM* toward trimethylphenol (TMP) attenuation (fTMP= 64 ± 4 M–1). This study provides new insights into the photochemical transformation of FAC in sunlit surface waters, and the results are applicable when sunlight/FAC system is employed as an advanced oxidation process.

Flexible wearable sensors can quantify and visualize the pressure, thus play important roles in practical applications such as medical monitoring, robotics, artificial skin, etc. High-porosity aerogel has excellent application potential in pressure sensor. However, aerogel is prone to irreversible deformation under long-term cycling pressure, which affects the performance of the sensor. How to balance high sensitivity and good cycle stability requires careful design of sensitive components. We propose a strategy to introduce the aerogel structure into the tiny sponge network, which greatly relieves the irreversible deformation and improves the long-cycle stability. A piezoresistive sponge (MGP-sponge) composed of triple morphological networks (MXene/rGO aerogel, PS spheres, and sponge) is obtained by electrostatic self-assembly, freeze-drying, and annealing. By filling the fragile MXene/rGO aerogel into sponge, the sensor could maintain more than 90% of initial sensitivity (224 kPa−1) after 15,000 cycles. It has the advantages of fast response time (63 ms), sensing bending extent, etc. The working mechanism of the MGP-sponge is revealed by in situFIB-SEM and first-principles calculations. MGP-sponge sensor performs excellently during various applications such as monitoring human activities, differentiating weights on a 2D array, controlling brightness of a LED sign, sensing manipulator finger motion, etc.

Fe(II)-catalyzed ferrihydrite transformation under anoxic conditions has been intensively studied, while such mechanisms are insufficient to be applied in oxic environments with depleted Fe(II). Here, we investigated expanded pathways of sunlight-driven ferrihydrite transformation in the presence of dissolved oxygen, without initial addition of dissolved Fe(II). We found that sunlight significantly facilitated the transformation of ferrihydrite to goethite compared to that under dark conditions. Redox active species (hole–electron pairs, reactive radicals, and Fe(II)) were produced from the ferrihydrite interface via the photoinduced electron transfer processes. Experiments with systematically varied wet chemistry conditions probed the relative contributions of three pathways for the production of hydroxyl radicals: (1) oxidation of water (5.0%); (2) reduction of dissolved oxygen (40.9%); and (3) photolysis of Fe(III)-hydroxyl complexes (54.1%). Results also showed superoxide radicals as the main oxidant for Fe(II) reoxidation under acidic conditions, thus promoting the ferrihydrite transformation. The presence of inorganic ions (chloride, sulfate, and nitrate) did not only affect the hydrolysis and precipitation of Fe(III) but also the generation of radicals via photoinduced charge transfer reactions. The involvement of redox active species and the accompanying mineral transformations would exert a profound effect on the fate of multivalent elements and organic contaminants in aquatic environments.

Hydrogen peroxide plays an important role in photochemical processes in aquatic environments. However, whether it can be transformed by photoexcited chromophoric dissolved organic matter (CDOM) remains unclear. Therefore, this study examined the photosensitized degradation of H2O2in CDOM-enriched solutions under simulated solar irradiation. Our results suggest that the presence of CDOM enhances the photodegradation rate of H2O2via the photosensitization process and ·OH is generated stoichiometrically with H2O2attenuation. Experimental results with model photosensitizers indicate that one-electron reducing species of CDOM (CDOM·–), not triplet CDOM, is the primary reactive species that reduces H2O2to yield ·OH. By monitoring the variation of CDOM·–, the reaction rate constant of CDOM·–with H2O2was estimated to be 1.5-fold greater than that with O2. Furthermore, a wastewater effluent was exposed to simulated solar irradiation with the addition of H2O2, and the results demonstrated that the photodegradation of trace organic contaminants (TrOCs) was significantly enhanced by the increased ·OH level. Overall, the current study provided new insights into the photochemical formation of ·OH via the one-electron reduction of H2O2by CDOM·–. The solar irradiation of wastewater with H2O2enhancement could be a useful and economically beneficial advanced oxidation process for TrOC abatement.