Photocatalytic hydrogen (H2) production is significant to overcome challenges like fossil fuel depletion and carbon dioxide emission, but its efficiency is still far below that which is needed for ...commercialization. Herein, we achieve long‐term stable H2 bubbling production from water (H2O) and lactic acid via visible‐light‐driven photocatalysis in a porous microreactor (PP12); the catalytic system benefits from photocatalyst dispersion, charge separation, mass transfer, and dissociation of O−H bonds associated with H2O. With the widely used platinum/cadmium‐sulfide (Pt/CdS) photocatalyst, PP12 leads to a H2 bubbling production rate of 602.5 mmol h−1 m−2, which is 1000 times higher than that in a traditional reactor. Even when amplifying PP12 into a flat‐plate reactor with an area as large as 1 m2 and extending the reaction time to 100 h, the H2 bubbling production rate still remains at around 600.0 mmol h−1 m−2, offering great potential for commercialization.
Long‐term stable H2 production from H2O via visible‐light‐driven photocatalysis using lactic acid as a sacrificial reagent and Pt/CdS as a photocatalyst is achieved in a porous microreactor (PP12), with a H2 production rate as high as 602.5 mmol h−1 m−2. PP12 can be scaled up to a flat‐plate reactor with an area as large as 1 m2, without a decrease in H2 production efficiency, offering great potential for commercialization.
More and more attention has been paid to the important roles of external fields in controlled radical polymerization (CRP). However, their essential roles have not been studied thoroughly yet, which ...hinders the in‐depth understanding of the mechanism and kinetics. Herein, a strategy combining quantum chemical calculations (QCC) and kinetic modeling was adopted to identify the essential roles of light and ultrasonication in the dual‐stimuli regulated bulk atom transfer radical polymerization (ATRP). At the molecular level, the impact of light on Cu‐catalyzed ATRP was investigated. The CuIIBr/Me6TREN has high absorbance at an experimental wavelength of 365 nm (main excitation S0 → D7 accounts for 84.93%). Electron transfer reactions involving Me6TREN are more favorable paths for photochemical reactions, and the mechanism of the copper activation/deactivation pathway is inner sphere electron transfer. At the micro‐scale, a kinetic model based on the method of moment was established with a “series” encounter pair model to consider the influence of ultrasound on diffusional limitation. Simulation results show that the changes of the reaction rate coefficients ka, kda, and kt at high conversion reflect the degree of diffusional limitation by ultrasound. The multiscale modeling strategy applied in this study identifies the essential roles of photo and ultrasonication in dual‐stimuli regulated model systems, which can be extended to other external‐field regulated CRP to improve the mechanistic understanding.
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•Advances in photocatalytic inactivation ability with g-C3N4-based nanomaterials.•Elucidates photocatalytic disinfection efficiency and possible reaction mechanism.•The latest design ...considerations of g-C3N4-based photocatalysts are described.
Microbial contamination in wastewater systems is a global problem and has attracted more and more attention. Therefore, a high-performance and environmentally friendly inactivation method is in great demand. Graphitic carbon nitride (g-C3N4) exhibits lots of prominent properties such as appealing physicochemical stability, unique two-dimensional structure and tunable electronic structure. Unsatisfactorily, the pristine g-C3N4 also faces the shortcomings arising from the limited visible light response and few active sites. Hence, a comprehensive review (“can we go further?”) about modified g-C3N4 photocatalysts for solar photocatalytic disinfection is necessary, which provides some inspiration for further optimization of the g-C3N4-based photocatalytic disinfection system. Meanwhile, the performance of g-C3N4-based photocatalysts for photocatalytic bacterial disinfection and the involved mechanisms are reviewed. In addition, the current prospects and possible challenges are pointed out. This review aims to summarize recent studies of g-C3N4-based photocatalysts in environmental disinfection and open a bright window to this booming research theme.
Soil contamination posed by potentially toxic elements is becoming more serious under continuously development of industrialization and the abuse of fertilizers and pesticides. The investigation of ...soil potentially toxic elements is therefore urgently needed to ensure human and other organisms’ health. In this study, we investigated the feasibility of the separate and combined use of portable X-ray fluorescence (pXRF) and visible near-infrared reflectance (vis-NIR) sensors for measuring eight potentially toxic elements in soil. Low-level fusion was achieved by the direct combination of the pXRF and vis-NIR spectra; middle-level fusion was achieved by the combination of selected bands of the pXRF and vis-NIR spectra using the Boruta feature selection algorithm; and high-level fusion was conducted by outer-product analysis (OPA) and Granger–Ramanathan averaging (GRA). The estimation accuracy for the eight considered elements were in the following order: Zn > Cu > Ni > Cr > As > Cd > Pb > Hg. The measurement for Cu and Zn could be achieved by pXRF spectra alone with Lin’s concordance correlation coefficient (LCCC) values of 0.96 and 0.98, and ratio of performance to interquartile distance (RPIQ) values of 2.36 and 2.69, respectively. The measurement of Ni had the highest model performance for high-level fusion GRA with LCCC of 0.89 and RPIQ of 3.42. The measurements of Cr using middle- and high-level fusion were similar, with LCCC of 0.86 and RPIQ of 2.97. The best estimation accuracy for As, Cd, and Pb were obtained by high-level fusion using OPA, with LCCC >0.72 and RPIQ >1.2. However, Hg measurement by these techniques failed, having an unacceptable performance of LCCC <0.20 and RPIQ <0.75. These results confirm the effectiveness of using portable spectrometers to determine the contents of several potentially toxic elements in soils.
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•pXRF and vis-NIR spectra used to measure contents of 8 potentially toxic elements in soil.•Three levels of data fusion were employed and compared.•Cu and Zn could be measured by pXRF spectra alone; neither spectra could measure Hg.•Other potentially toxic elements were best measured by high-level fusion of both spectra.
Capsule: Soil potentially toxic elements could be estimated rapidly with good accuracy by portable spectrometers and sensor fusion could further improve estimation accuracy.
Chitosan is a promising adsorbent for removing a wide range of pollutants from wastewater. However, its practical application is hindered by instability in acidic environments, which significantly ...impairs its adsorption capacity and limits its utilization in water purification. While cross-linking can enhance the acid stability of chitosan, current solvent-based methods are often costly and environmentally unfriendly. In this study, a solvent-free mechanochemical process was developed using high-energy ball milling to cross-link chitosan with various polyanionic linkers, including dextran sulfate (DS), poly4-styrenesulfonic acid-co-maleic acid (PSSM), and tripolyphosphate (TPP). The mechanochemically cross-linked (MCCL) chitosan products exhibited superior adsorption capacity and stability in acidic solutions compared to pristine chitosan. Chitosan cross-linked with DS (Cht-DS) showed the highest Reactive Red 2 (RR2) adsorption capacity, reaching 1559 mg·g−1 at pH 3, followed by Cht-PSSM (1352 mg·g−1) and Cht-TPP (1074 mg·g−1). The stability of MCCL chitosan was visually confirmed by the negligible mass loss of Cht-DS and Cht-PSSM tablets in pH 3 solution, unlike the complete dissolution of the pristine chitosan tablet. The MCCL significantly increased the microhardness of chitosan, with the order Cht-DS > Cht-PSSM > Cht-TPP, consistent with the RR2 adsorption capacity. When tested on simulated rinsing wastewater from chromium electroplating, Cht-DS effectively removed Cr(VI) (98.75% removal) and three per- and polyfluoroalkyl substances (87.40–95.87% removal), following pseudo-second-order adsorption kinetics. This study demonstrates the potential of the cost-effective and scalable MCCL approach to produce chitosan-based adsorbents with enhanced stability, mechanical strength, and adsorption performance for treating highly acidic industrial wastewater containing a mixture of toxic pollutants.
Deep eutectic solvent (DES) is used as both photocatalyst and solvent for photoinduced reversible complexation‐mediated polymerization (photo‐RCMP), which enables a rapid polymerization to produce ...polymers with predictable molar mass and low molar mass dispersity (Đ). This work illustrates a comprehensive understanding of DES‐accelerated RCMP's mechanism and kinetic features through quantum chemical calculations and kinetic modeling. According to the results, electrons transferring from hydrogen bond in DES to iodine atom in alkyl iodide (RI) initiator under light irradiation lowers the decomposition free energy of complex RI‐DES. This procedure facilitates the generation of primary radicals, thus contributing to the DES‐accelerated phenomenon. In the meantime, the reaction paths are identified by computation as (i) decomposition of RI‐DES under light irradiation generates active radicals and ·I‐DES complex and (ii) combination of two ·I‐DES releases iodine (I2) and regenerates DES. In addition, kinetic modeling based on the method of moments successfully identifies kinetic features of polymerization in the presence and absence of DES, respectively. Kinetic modeling shows a fast increase in primary radicals concentration and rapid build‐up of the photo‐RCMP activation‐deactivation equilibrium, demonstrating that DES is a beneficial photocatalyst and solvent to enable the rapid generation of primary radicals and accelerate the completion of catalytic cycle. This research provides an in‐depth understanding of DES‐involved photo‐RCMP and lays a theoretical foundation for expanding the application of DES to other polymerization systems.
A comprehensive kinetic Monte Carlo (kMC) model of a reaction–diffusion system has been developed to illustrate the heterogeneous reaction of electrochemically mediated atom transfer radical ...polymerization (eATRP). The equilibrium coefficient for the initiator obtained from the Genetic Algorithm was lower than that for polymeric species, explaining the low initiation efficiency of the iron‐based eATRP of methyl methacrylate (MMA) system. A comparative study demonstrated that the composite kt model, explicitly considering the chain length dependency, presented the most adequate description of the polymerization kinetic behaviors to account for diffusional limitations on termination. In addition, a positive effect of the applied potential on the apparent polymerization rate was observed, and an exponential regression equation correlating the reduction rate coefficient and the applied potential was obtained. Attractively, simulation results indicated the viscosity effect on the mass transfer using the model based on free volume theory enhanced the controllability and livingness of the system.
During the first 100 years of polymer science, controlled radical polymerization (also recommended as reversible deactivation radical polymerization) is undoubtedly a revolutionary discovery. Owing ...to the mild reaction conditions, the broad applicability, and the accessibility to produce well-defined functional polymers, controlled radical polymerization has gained a plethora of interest from both academia and industry. In this review, the efforts made by both polymer chemistry and reaction engineering communities to fully exploit the potential of controlled radical polymerization in precision polymer synthesis are retrospected. Highlights on how the synergetic experimental and modeling tools can offer the unique information on the mechanistic understanding, kinetic insights, and the chain microstructures tuning are provided. Future research directions in this area are also outlined. Hopefully, this review can stimulate future developments of controlled radical polymerizations in the next 100 years of polymer science.
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To overcome the limitations of empirical synthesis and expedite the discovery of new polymers, this work aims to develop a data‐driven strategy for profoundly aiding in the design and screening of ...novel polyester materials. Initially, we collected 695 polyesters with their associated glass transition temperatures (Tgs) to develop a quantitative structure–property relationship (QSPR) model. The model underwent rigorous validation (i.e., external validation, internal validation, Y‐random, and application domain analysis) to demonstrate its robust predictive capabilities and high stability. Subsequently, by employing an in‐silico retrosynthesis strategy, over 95,000 virtual polyesters were designed, largely expanding the available space for polyester material family. External assessments were performed, highlighting good extrapolation ability of the QSPR model. Furthermore, we experimentally synthesized 10 designed polyesters with predicted Tgs covering a large temperature range from −42.52 to 103.61°C, and characterization results gave an average absolute error of 17.40°C relative to the predicted ones. It is believed that such data‐driven approach can drive future product development of polymer industry.
Reversible‐deactivation radical polymerization (RDRP) techniques have received lots of interest for the past 20 years, not only owing to their simple, mild reaction conditions and broad ...applicability, but also their accessibility to produce polymeric materials with well‐defined structures. Modeling is widely applied to optimize the polymerization conditions and processes. In addition, there are numerous literatures on the kinetic and reactor models for RDRP processes, which show the accessibility on polymerization kinetics insight, process optimization, and controlling over chain microstructure with predetermined molecular weight and low dispersity, copolymer composition distribution, and sequence distribution. This review highlights the facility of the method of moments in the modeling field and presents a summary of the present state‐of‐the‐art and future perspectives focusing on the model‐based RDRP processes based on the method of moments. Summary on the current status and challenges is discussed briefly.
There are numerous literatures on the kinetic and reactor models for reversible‐deactivation radical polymerization (RDRP) processes, which show the accessibility on polymerization kinetics insight, process optimization, and controlling over chain microstructure. This work highlights the facility of the method of moments in the modeling field and presents a summary of the present state‐of‐the‐art and future perspectives focusing on the model‐based RDRP processes based on the method of moments. Summary on the current status and challenges is discussed briefly.
