Undesirable By-products Research Articles

Second-generation biorefineries: single platform for the conversion of lignocellulosic wastes to environmentally important biofuels.

The continuously increasing demands for various fossil fuels to achieve the day-to-day needs of the human population are growing and causing adverse effects on the environment and leading to the depletion of their natural resources. To overcome such drastic problems and minimize the production of greenhouse gases, lignocellulose biomass, which is an abundant and bio-renewable source present on earth with excellent properties and composition, has been used for decades to develop biofuels that can easily take over the place of conventional fuels. Lignocellulose biomass comprises polymeric sugars, i.e., cellulose and hemicellulose, and aromatic polymer, lignin, which are responsible for producing various bio-based products. However, utilizing lignocellulosic wastes for such purposes is needed but their recalcitrant structure makes it difficult to achieve their full usage. For this, several pretreatment approaches are developed to loosen the complexity between sugars and lignin. In some way, few of the conventional pretreatment methods are expensive, non-eco-friendly, and produce undesired by-products, causing a lower yield and reusability of enzymes used in the reaction. Utilizing novel pretreatment strategies that are cost-effective, help in increasing the yield of products, and are environment-friendly is required. Thus, incorporating nanoparticles and nanomaterials in the development of pretreatment and other strategies for the production of bio-based products is currently thriving. This review is designed in such a way that the readers can easily get brief knowledge about the production of important biofuels developed within second-generation biorefineries using lignocellulosic biomass. It also summarizes the importance of nanotechnology in different steps of biofuel development.

Comprehensive stable-isotope tracing of glucose and amino acids identifies metabolic by-products and their sources in CHO cell culture

Mammalian cell culture processes are widely utilized for biotherapeutics production, disease diagnostics, and biosensors, and hence, should be optimized to support robust cell growth and viability. However, toxic by-products accumulate in cultures due to inefficiencies in metabolic activities and nutrient utilization. In this study, we applied comprehensive 13C stable-isotope tracing of amino acids and glucose to two Immunoglobulin G (IgG) producing Chinese Hamster Ovary (CHO) cell lines to identify secreted by-products and trace their origins. CHO cells were cultured in media formulations missing a single amino acid or glucose supplemented with a 13C-tracer of the missing substrate, followed by gas chromatography-mass spectrometry (GC-MS) analysis to track labeled carbon flows and identify by-products. We tracked the sources of all secreted by-products and verified the identity of 45 by-products, majority of which were derived from glucose, leucine, isoleucine, valine, tyrosine, tryptophan, methionine, and phenylalanine. In addition to by-products identified previously, we identified several metabolites including 2-hydroxyisovaleric acid, 2-aminobutyric acid, L-alloisoleucine, ketoisoleucine, 2-hydroxy-3-methylvaleric acid, desmeninol, and 2-aminobutyric acid. When added to CHO cell cultures at different concentrations, certain metabolites inhibited cell growth while others including 2-hydroxy acids, surprisingly, reduced lactate accumulation. In vitro enzymatic analysis indicated that 2-hydroxy acids were metabolized by lactate dehydrogenase suggesting a possible mechanism for lowered lactate accumulation, e.g., competitive substrate inhibition. The 13C-labeling assisted metabolomics pipeline developed and the metabolites identified will serve as a springboard to reduce undesirable by-products accumulation and alleviate inefficient substrate utilization in mammalian cultures used for biomanufacturing and other applications through altered media formulations and pathway engineering strategies.

Black Silicon Surface-Enhanced Raman Spectroscopy Biosensors: Current Advances and Prospects.

Black silicon was discovered by accident and considered an undesirable by-product of the silicon industry. A highly modified surface, consisting of pyramids, needles, holes, pillars, etc., provides high light absorption from the UV to the NIR range and gives black silicon its color-matte black. Although black silicon has already attracted some interest as a promising material for sensitive sensors, the potential of this material has not yet been fully exploited. Over the past three decades, black silicon has been actively introduced as a substrate for surface-enhanced Raman spectroscopy (SERS)-a molecule-specific vibrational spectroscopy technique-and successful proof-of-concept experiments have been conducted. This review focuses on the current progress in black silicon SERS biosensor fabrication, the recent advances in the design of the surface morphology and an analysis of the relation of surface micro-structuring and SERS efficiency and sensitivity. Much attention is paid to problems of non-invasiveness of the technique and biocompatibility of black silicon, its advantages over other SERS biosensors, cost-effectiveness and reproducibility, as well as the expansion of black silicon applications. The question of existing limitations and ways to overcome them is also addressed.

Continuous Monitoring of Monochloramine in Water, and Its Distinction from Free Chlorine and Dichloramine Using a Functionalized Graphene-Based Array of Chemiresistors.

Monochloramine (MCA) is commonly added to drinking water as a disinfectant to prevent pathogen growth. The generation of MCA at the treatment plant requires tight control over both pH and the ratio of free chlorine (FC) to ammonia to avoid forming undesirable byproducts such as dichloramine (DCA) and trichloramine (TCA), which can impart odor and toxicity to the water. Therefore, continuous monitoring of MCA is essential to ensuring drinking water quality. Currently, standard colorimetric methods to measure MCA rely on the use of reagents and are unsuitable for online monitoring. In addition, other oxidants can interfere with MCA measurement. Here, we present a solid-state, reagent-free MCA sensing method using an array of few-layer graphene (FLG) chemiresistors. The array consists of exfoliated FLG chemiresistors functionalized with specific redox-active molecules that have differential responses to MCA, FC, and DCA over a range of concentrations. Chemometric methods were employed to separate the analytes' responses and to generate multivariate calibration for quantification. A minimum of three sensors are required in the array to maintain full functionality. The array has been demonstrated to quantify MCA in buffered and tap water as a low-cost, reagent-free approach to continuous monitoring.

Novel eco-friendly and easily recoverable bismuth-based materials for capturing and removing polyphenols from water

Olive oil production is one of the most developed Europe's sectors, producing olive oil and undesirable by-products, such as olive mill wastewater (OMWW) and organic waste. OMWW, containing large amounts of compounds (mainly polyphenols, phenols, and tannins), represents a problem. In fact, polyphenols have dual nature: i) antioxidant beneficial properties, useful in many industrial fields, ii) biorefractory character making them harmful in high concentrations. If not properly treated, polyphenols can harm biodiversity, disrupt ecological balance, and degrade water quality, posing risks to both environment and human health. From a circular economy viewpoint, capturing large quantities of polyphenols to reuse and removing their residuals from water is an open challenge. This study proposes, for the first time, a new path beyond the state-of-the-art, combining adsorption and degradation technologies by novel, eco-friendly and easily recoverable bismuth-based materials to capture large amounts of two model polyphenols (gallic acid and 3,4,5-trimethoxybenzoic acid), which are difficult to remove by traditional processes, and photodegrade them under solar light. The coupled process gave rise to collect 98% polyphenols, and to rapidly and effectively photodegrade the remaining portion from water.

Exhaust purification of stoichiometric natural gas applications – A screening study on the impact of catalyst composition, reaction conditions and transient effects

A set of model catalysts with a variation of precious metal components comprising Pt, Pd or Pt/Pd on typical support materials (CeO2, Al2O3 and ZrO2) is evaluated in a gas mixture simulating the exhaust gas of stoichiometric natural gas-fueled engines. Three-way catalytic (TWC) performance, especially CH4 conversion, is assessed in λ-sweep as well as dynamic light-Off/light-Out tests, both with oscillating feed (1 s lean /1 s rich) implemented on a fully automated reactor system. The transient response of catalysts to changing redox potential is demonstrated in tests with varying lean/rich duration and pseudo-stationary tests. Time resolved data clearly indicate that performance and stability depend on both, precious metal composition as well as support material. Beyond screening of catalyst activity, the focus was on factors affecting the formation of undesired by-products (e.g. NH3, N2O) on hydrothermally aged catalysts. Aging severity was introduced as additional dimension in the design of the experimental study.

Engineering atomic Rb-N configurations to tune radical pathways for highly selective photocatalytic H2O2 synthesis coupled with biomass valorization

Photocatalytic oxygen reduction for hydrogen peroxide (H₂O₂) synthesis presents a green and cost-effective production method. However, achieving highly selective H₂O₂ synthesis remains challenging, necessitating precise control over free radical reaction pathways and minimizing undesirable oxidative by-products. Herein, we report for the visible light-driven simultaneous co-photocatalytic reduction of O2 to H2O2 and oxidation of biomass using the atomic rubidium-nitride modified carbon nitride (CNRb). The optimized CNRb catalyst demonstrates a record photoreduction rate of 8.01 mM h−1 for H2O2 generation and photooxidation rate of 3.75 mM h−1 for furfuryl alcohol to furoic acid, achieving a remarkable solar-to-chemical conversion (SCC) efficiency of up to 2.27%. Experimental characterizations and DFT calculation disclosed that the introducing atomic Rb–N configurations allows for the high-selective generation of superoxide radicals while suppressing hydroxyl free radical formation. This is because the Rb–N serves as the new alternative site to perceive a stronger connection position for O2 adsorption and reinforce the capability to extract protons, thereby triggering a high selective redox product formation. This study holds great potential in precisely regulating reactive radical processes at the atomic level, thereby paving the way for efficient synthesis of H2O2 coupled with biomass valorization.

Ozonation: Post-harvest processing of different fruits and vegetables enhancing and preserving the quality

Daily ingestion of fresh produce has increased tremendously due to a rise in awareness of its nutritional benefits that contribute to reducing health risks and disease. However, these commodities are highly perishable and prone to significant post-harvest losses. Conventional methods have been scrutinized in the production of undesirable by-products. Ozone technology has emerged as an efficient sterilization technique. Additionally, it stimulated the synthesis of bioactive and antioxidant compounds by activating secondary metabolic pathways. However, there are conflicting findings in the literature related to their impact on the quality and physiological processes of fruits and vegetables (F&V). This scientific literature review focuses on key studies examining the effects of ozonation on the growth of microorganisms and the quality preservation of different F&V. This review also enlarges our understanding of eco-friendly technologies which not only extend the shelf life of F&V but also uphold their quality without introducing harmful chemicals.

Insight into immobilization mechanisms of metal/metalloid ions and herbicide molecules on waste-derived Na-X zeolite covered with macromolecules

Immobilization of toxic compounds on the solids limits their bioavailability in natural ecosystems. The use of waste-derived adsorbents for this purpose has additional benefit – the possibility of managing undesirable and dangerous by-products. Thus, the main aim of the study was to explore immobilization mechanism of metals (Cd, Cu), metalloids (As, Se), and herbicides (diuron, glyphosate) on zeolite Na-X free of ash residue, coming from waste solution after high carbon fly ash (HiC FA) conversion, under specific conditions – in multicomponent solutions as well as after solid modification with polymers. Immobilization strength was assessed based on adsorption/desorption studies, whereas the solid surface was investigated by XPS, FTIR, SEM-EDS, etc. The results obtained for Na-X was compared with those measured for its precursor, HiC FA. It was found that Na-X was a good adsorbent of Cu(II) and Cd(II) cations – it bound 195.8 mg/g (58.7 %) of Cd(II) and 126.9 mg/g (38.1 %) of Cu(II) mainly in the form of hydroxides. The Na-X modification with polymers made its adsorption capacity towards metalloid anions and herbicides higher. Anionic polyacrylamide increased the Se(IV) adsorption from 0.2 to 67.5 mg/g. Cationic polyacrylamide contributed to higher immobilization of glyphosate and diuron by 43.9 % and 46.4 %, respectively.

In-situ carbon-doped poly(triazine imide) modified with silver nanoparticles for synergistic efficient photocatalytic CO2 reduction coupled with biomass refining

Solar-driven CO2 reduction to fuels holds critical importance in addressing climate and energy challenges. However, the practical application faces limitations due to the difficulty in activating CO2, the slow kinetics of the oxidation half-reaction, and the generation of undesired by-products. Herein, we report a functionally-oriented approach for the deliberate fabrication of in-situ carbon-doped poly(triazine imide) modified with silver nanoparticles (Ag NPs) (Ag/C@PTI), aimed at solar-driven CO2 reduction synchronized with xylose oxidation within a single redox cycle. The strategic in-situ carbon doping and the deposition of Ag NPs significantly reduce the bandgap of PTI to 1.60 eV, thereby markedly enhancing charge carrier separation and refining product selectivity. Consequently, the optimally formulated Ag10/C@PTI-10 catalyst demonstrates superior photocatalytic performance in xylose oxidation coupled with CO2 reduction, achieving a xylonic acid yield of 51.4 % and a CO evolution rate of 31.4 μmol g-1h-1. The 13CO2 isotope labeling experiments confirm that a portion of the CO is derived from the xylose conversion process. Moreover, ESR characterization along with capture tests reveal that h+ and ·O2- are pivotal in the photooxidation of xylose to xylonic acid.

Tailoring photocatalysts to modulate oxidative potential of anilides enhances para-selective electrochemical hydroxylation

Phenolic compounds have long captivated the interest of organic synthesis, particularly in their quest for selective hydroxylation of arenes using H2O as a hydroxyl source. However, the inherent high reactivity and low redox potential of phenols often lead to undesirable overoxidation byproducts. To address this challenge, herein, we develop an electrophotochemical approach, finetuning substrate oxidative potential and enabling para-selective hydroxylation of anilides. This method showcases versatility, accommodating a wide array of substrates, while revealing high regional selectivity and compatibility with diverse functional groups. Moreover, the protocol allows facile late-stage functionalization of biologically active molecules. Mechanistic investigations demonstrate the activation of anilides by the excited state photocatalyst, effectively decreasing their oxidative potential and enhancing regional selectivity during hydroxylation. By using this protocol, important drug molecules such as Paracetamol, Fenretinide, Practolol, and AM404 could be synthesized, demonstrating the applicability of this approach in drug synthesis and late-stage functionalization.

Novel Cu(200)/Ti cathode for the enhancement of N2 selectivity in direct ammonia electrolysis: The controls of Cu cathode facet orientation

Direct electrochemical ammonia oxidation reaction (AOR) using NiCu-based anodes is effective in removing ammonia from wastewater. However, this type of anode frequently produces undesired byproducts NO3−. Here, we investigated three configurations of novel Cu/Ti cathodes (Cu(111)/Ti, Cu(200)/Ti, Cu(220)/Ti) coupled with Cu/Ni foam (Cu/NF) anode to enhance N2 selectivity (SN2) in a direct ammonia electrolysis cell. Cu(200)/Ti cathode improved SN2 from 35 % (bare Ti cathode) to 60 % and it achieved 10–15 % higher SN2 compared to Cu(111)/Ti and Cu(220)/Ti. The improvement of SN2 on Cu(200) facet was ascribed to the high nitrate electroreduction activity and its conversion to N2. In real wastewater, Cu/NF anode-Cu(200)/Ti cathode paired electrolysis system demonstrated its excellent capability of 88 % NH3 removal with 95 % SN2. Our electrolysis system was capable to maintain the residual NH3-N and the NO3-N below 8 mg L−1, meeting effluent discharge standards. Our findings highlighted the importance of the control of Cu cathode facet orientations for an efficient elimination of NO3– and improvement of N2 production during direct ammonia electrolysis.

Cobalt Nanoparticles Supported Active Carbon from Chitosan Biopolymer Using Thermal Method: Synthesis, Characterization, and Hydrogen Production

AbstractActivated carbon based Cobalt nanoparticles (Co@AC NPs), considered in the context of hydrogen energy, which is a renewable and sustainable energy, were synthesized by the hydrothermal method, and their catalytic activities were tested. For this, hydrogen production tests were carried out with the help of sodium borohydride (NaBH4) methanolysis of Co@AC NPs synthesized by the thermal method. Ultraviolet–visible spectroscopy (UV–Vis), Fourier transmission spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD) characterization tests were performed. According to the TEM characterization result, it has been observed that the NPs have a spherical shape and an average size of 2.52 ± 0.92 nm. Then, using the catalytic studies, it was observed that hydrogen production’s reusability is found to be 86% . The activation energy (Ea), enthalpy (∆H), and entropy (∆S) values were found to be 20.28 kJ⋅mol−1, 17.74 kJ⋅mol−1, and −125.97 J⋅mol−1 K−1, respectively. The obtained values have yielded excellent results and guide future sustainable and renewable hydrogen energy studies by reducing costs, ensuring environmental sustainability by avoiding the formation of undesirable by-products, and producing hydrogen from NaBH4 through its high catalytic properties.

H2S mitigation for biogas upgrading in a full-scale anaerobic digestion process by using artificial neural network modeling

Biogas production by anaerobic digestion (AD) has emerged as a prominent bio-renewable energy source in recent years. However, the process also produces undesirable by-products, including H2S, thereby negatively impacting the biogas quality. This study focused on mitigating H2S in a full-scale AD located at a wastewater treatment plant (WWTP) by controlling the internal operational parameters by using an artificial neural network (ANN) model. Data from 54 days of AD operation were used to train and validate a structured ANN with a 5-3-1 topology. To minimize the H2S content, optimum values for dry solid (DS), volatile solid (VS), pH, temperature, and primary sludge fraction (PS) were determined to be 6.2 %, 63 %, 7.7, 35.6 °C, and 67.6 %, respectively, using the particle swarm optimization (PSO) algorithm. This optimization indicated a 49 % reduction in the average H2S concentration, from 6117 ppm to 3107 ppm. The analysis of relative importance (RI) showed that the pH (RI = −29.5) and PS (RI = −28.7) were the most critical factors affecting biogas quality. Additionally, several solutions derived from the optimization results were practically implemented in the Qom WWTP to achieve optimal conditions, and the outcomes were discussed.

Decoding the Effect of Synthesis Factors on Morphology of Nanomaterials: A Case Study to Identify and Optimize Experimental Conditions for Silver Nanowires

Silver nanowires (AgNWs) are one kind of nanomaterials for various applications such as solar panel cells and biosensors. However, the morphology of AgNWs, particularly their length and diameter, plays a critical role in determining the efficiency of energy storage systems and the transmittance of biosensors. Thus, it is imperative to study synthesis strategy for morphology control. This study focuses on synthesizing AgNWs through the solvothermal approach and aims to understand the individual and combined effects of three nucleants, NaCl, Fe(NO3)3 and NaBr, on the morphology of AgNWs. Using a modified successive multistep growth (SMG) approach and fine-tuning the nucleant concentrations, this study synthesized AgNWs with controllable aspect ratios, while minimizing the presence of undesirable byproducts like nanoparticles. Our results demonstrated the successful synthesis of AgNWs with favorable morphologies, including lengths of approximately 180 µm and diameters of 40 nm, thus resulting in aspect ratios of 4500. In addition, to assess the quality of the synthesized AgNWs, this work developed computational tools that uses MATLAB to automate the analysis of scanning electron microscope (SEM) images for detecting silver nanoparticles. This automated approach provides a quantitative analysis tool for material characterization and holds the promise for long-term evaluation of diverse AgNW samples, thereby paving the way for advancements in their synthesis and application. Overall, this study demonstrates the significance of morphology control in AgNW synthesis and presents a robust framework for material characterization and quality analysis.

Synergistic co-steam gasification of biomass and refuse-derived fuel: A path to enhanced gasification performance

The co-steam gasification of biomass (straw) and Refuse-Derived Fuel (RDF) presents a promising pathway for sustainable waste management and renewable energy production, with significant implications for environmental protection. This study investigates the co-gasification of straw and RDF to optimize syngas production and minimize undesired by-products. The optimization of the S/M ratio and gasification temperature is crucial for efficient RDF gasification. The optimal S/M ratio and temperature balance syngas yield, quality (LHV), and process efficiency (carbon conversion efficiency and cold gas efficiency), while minimizing environmental hazards from solid residues. The carbon conversion efficiency of co-gasification of RDF increased by 12.7 % at the S/M 0 f 0.75 and gasification temperature of 800°C, a significant improvement compared to the efficiencies observed for the separate gasification of straw and RDF. Additionally, the gas yield and the cold gas efficiency were increased by 14.43 % and 26.42 % compared to the separate gasification processes, respectively. These results demonstrate the synergistic effects of co-gasifying straw and RDF, enhancing gasification performance and reducing tar formation. The study underscores the potential of co-steam gasification of straw and RDF as a technologically viable and environmentally friendly approach to waste-to-energy conversion, emphasizing the importance of operational optimization for achieving superior energy recovery, resource efficiency, and reduced environmental impact.

Boosting the activity of BiVOx via vanadium-promotion for highly selective oxidation of biomass-derived xylose toward formic acid

Formic acid is a versatile and promising value-added chemical derived from the chemoselective transformation of renewable biomass resources. However, achieving a high production rate of formic acid remains a pivotal and enormous challenge. Herein, we synthesized a sequence of BiVOx catalysts based on vanadium-promotion by a facile and cost-effective strategy for selective oxidation of biomass-derived xylose in water under O2 atmosphere. Particularly, the resultant Bi1V2Ox exhibited a remarkably enhanced catalytic activity, higher selectivity toward formic acid, and excellent recyclability, giving a yield of 75.8 % and a production rate of formic acid (9.22 mol FA molV−1h−1) at 170 °C within only 20 min. Such pronounced improved performance was largely attributed to the synergistic effect between V and Bi species, with higher surface area, abundant surface acidity, as well as stronger adsorption energy, meanwhile efficiently suppressing the formation of undesired by-products. This study demonstrates that the promotion of V in BiVOx leads to more efficient catalytic oxidation of xylose to formic acid, and with further driven research that proved great potential for generating formic acid from renewable biomass resources for future industrial application.

Revisit coupling of CO2 to ethylene carbonate with an integrated imidazolium and zinc halides catalyst by a study on its decomposition: Active center and mechanism

Coupling of carbon dioxide (CO2) to cyclic carbonates with an epoxide and further into linear carbonates as the indispensable solvents for the lithium-ion batteries has been being one of the hottest topics in transforming CO2 into high value-added chemicals. Nevertheless, the extremely ultrahigh purity requirement for them causes a low efficiency and a modest yield due to the undesired reactions and byproducts occurring in the separation and purification sections. In this work, a novel imidazolium based ionic liquid catalyst system with different anions and cations was studied by a thorough insight into the decomposition reaction of ethylene carbonate (EC), which reveals the synergistic mechanism of the composite catalysts both in section of cyclic carbonate separation from the catalyst for recirculated utilization and purification from the byproducts, and in section of synthesis with high efficiency. Effects of imidazolium cations and halogen anions in the ionic liquid molecule on EC decomposition were investigated by the elaborately designed experiments, thermodynamic estimations, molecular dynamics simulation and DFT assessment. It was found that combining imidazole salts and zinc halides can greatly boost the activity of EC synthesis and decomposition with the effective structure of catalytic center being [EMIm]ZnX4. Furthermore, it was indicated that Br- has a higher activity for EC synthesis and its reversed pyrolysis, while Cl- will promote a side reaction of ring-opening polymerization of EC. Finally, a most favorable catalyst composition with ZnBr2 and [EMIm]Br for EC synthesis was achieved with a high efficiency in synthesis and a low tendency to initiate the side reactions in separation section.

Assessment of organic solvents for 2,5-furandicarboxylic acid (FDCA) and distribution in water/cyclohexanone biphasic system

2,5-furandicarboxylic acid (FDCA) is one of the most promising sugar-derived building blocks aimed to produce greener polymers, such as the 100 % recyclable bioplastic polyethylene furanoate (PEF). One incipient field of research is the development of liquid–liquid biphasic systems for FDCA production from 5-hydroxymethylfurfural (HMF) to increase selectivity and minimize undesirable by-product formation. In this work, we first performed an assessment of potential organic green solvents to form biphasic systems considering operability, along with safety, health, and environmental implications. This analysis guided the selection of eight organic solvents in which the solubility of FDCA was measured: cyclohexanone, diethyl ether, isobutyl acetate, methyl isobutyl ketone, methyl ethyl ketone, methoxycyclopentane, tert-butylmethyl ether, and octan-1-ol. The results revealed the superior performance of cyclohexanone as a solvent for the organic phase/water FDCA distribution owing to its higher FDCA solubility (1.364 g/L at 293.15 K). Thus, the FDCA distribution coefficient (KFDCA) between water and cyclohexanone was examined at several temperatures (293.15–313.15 K) and various initial aqueous concentrations to gain deeper insight into the thermodynamics of the phase transfer process and the influence of pH on FDCA distribution between water and cyclohexanone. The resulting enthalpy and entropy of transfer were −15.3 ± 1.0 kJ mol−1 and −44.9 ± 4.6 J K−1 mol−1, thus the highest value of KFDCA (4.83) was obtained at 293.15 K, together with a very high separation factor (81.5) which shows the great potential of cyclohexanone to extract FDCA from aqueous solutions.

Effective inhibition of chloride ion interference in photocatalytic process by negatively charged molecularly imprinted photocatalyst: Behavior and mechanism

The ubiquitous chloride ions (Cl−) in water seriously interfere with pollutant oxidation and inevitably generate undesirable chlorinated byproducts. In this study, we report for the first time that a negatively charged molecularly imprinted photocatalyst (MIP) can effectively inhibit Cl− interference and suppress the production of chlorination byproducts (the yield of chloroacetic acid was only 16 % of the bare photocatalyst system) while ensuring efficient degradation of target pollutants, thereby greatly improving the safety of the pollutant degradation process. Taking antibiotics as target pollutant, we investigated the mechanism of action of MIP by comparing the antibiotic degradation pathways, fate of photogenerated active species and production of reactive chlorine species (RCS) in the MIP and bare photocatalyst system. The mechanism by which MIP inhibits Cl− interference was mainly based on a synergy between electrostatic repulsion and steric hindrance induced by the specific capture of antibiotics in imprinted cavity, which effectively suppressed the production of RCS and hindered the participation of RCS in antibiotics degradation. In addition, MIP showed good compatibility with common cations, anions and organic matter, and performed well within a broad pH range in various water environments. Thus, the negatively charged MIP provides a feasible approach for the safe and efficient removal of pollutants in Cl− containing water.