Phase State Regulates Photochemical HONO Production from NaNO3/Dicarboxylic Acid Mixtures.

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., NaNO3 and 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 PHONO once 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.

Spectral Characteristics of Unsaturated and Supersaturated Inorganic Aerosols: Insights into Deliquescence Kinetics.

The deliquescence phase transition of atmospheric aerosols is crucial for radiative forcing and atmospheric chemistry. However, the deliquescence kinetics of micrometer-sized aerosols, especially the formation and evolution of surface solution films, remain poorly understood. In this study, IR spectral characteristics were employed for the first time to quantify the solute concentration evolution in surface solution films. At a constant relative humidity (RH) of ∼65%, solution films on NaCl crystals exhibited a very low solute concentration (3.06 ± 0.18 mol/L), comparable to aqueous NaCl droplets above 90% RH. These films reached saturation at ∼74% RH, i.e., the deliquescence RH of NaCl, maintaining a nearly constant saturation level during deliquescence. In contrast, amorphous NaNO3 solids showed supersaturated solution films before deliquescence. Following deliquescence, the saturation level of solution phases increased due to faster solid dissolution rates than liquid water condensation. These findings address knowledge gaps in the complex nonequilibrium dissolution processes of crystalline or amorphous atmospheric aerosols.

Heterogeneous uptake of NO2 by sodium acetate droplets and secondary nitrite aerosol formation.

The high NO3- concentration in fine particulate matters (PM2.5) during heavy haze events has attracted much attention, but the formation mechanism of nitrates remains largely uncertain, especially concerning heterogeneous uptake of NOX by aqueous phase. In this work, the heterogeneous uptake of NO2 by sodium acetate (NaAc) droplets with different NO2 concentrations and relative humidity (RH) conditions is investigated by microscopic Fourier transform infrared spectrometer (micro-FTIR). The IR feature changes of aqueous droplets indicate the acetate depletion and nitrite formation in humid environment. This implies that acetate droplets can provide the alkaline aqueous circumstances caused by acetate hydrolysis and acetic acid (HAc) volatilization for nitrite formation during the NO2 heterogeneous uptake. Meanwhile, the nitrite formation will exhibit a pH neutralizing effect on acetate hydrolysis, further facilitating HAc volatilization and acetate depletion. The heterogeneous uptake coefficient increases from 5.2 × 10-6 to 1.27 × 10-5 as RH decreases from 90% to 60% due to the enhanced HAc volatilization. Furthermore, no obvious change in uptake coefficient with different NO2 concentrations is observed. This work may provide a new pathway for atmospheric nitrogen cycling and secondary nitrite aerosol formation.

Retracted: Mukonal Inhibits Cell Proliferation, Alters Mitochondrial Membrane Potential and Induces Apoptosis and Autophagy in Human CNE1 Nasopharyngeal Carcinoma Cells.

Retracted, due to breach of publishing guidelines, following the identification of non-original content. Reference: Mukonal Inhibits Cell Proliferation, Alters Mitochondrial Membrane Potential and Induces Apoptosis and Autophagy in Human CNE1 Nasopharyngeal Carcinoma Cells Yingyuan Guo, Yanru Hao, Guofang Guan, Shuaishuai Ma, Zhiling Zhu, Fang Guo, Jie Bai Med Sci Monit 2019; 25:1976-1983 10.12659/MSM.913915.

Microwave-assisted synthesis of 3D Bi2MoO6 microspheres with oxygen vacancies for enhanced visible-light photocatalytic activity.

Oxygen vacancies (OVs) defects in metal oxide-based photocatalysts play a crucial role in improving the charge carrier separation efficiencies to enhance the photocatalytic performances. In this work, OVs were introduced in 3D Bi2MoO6 microspheres through a facile and fast microwave-assisted method via the modulation of tetramethylethylenediamine (TMEDA). EPR, Raman and XPS results demonstrated that large amounts of oxygen vacancies were formed on the surface of BMO microspheres. The photocatalytic properties of the samples were studied by degradation of tetracycline (TC) under visible light. The optimal Bi2MoO6 with OVs exhibited optimum photocatalytic activity, and the degradation rate was 7.0 times higher than that of pristine Bi2MoO6. This enhancement can be attributed to the 3D structure furnishing more surface active sites and suitable OVs defects favoring the electron-hole separation. Moreover, the defective Bi2MoO6 microspheres exhibit high stability because the photocatalytic activity remains almost unchanged after 5 cycles, making them favorable for practical applications. Finally, a possible visible light photocatalysis mechanism for the degradation of TC was tentatively proposed.

Hygroscopic Growth and Phase Transitions of Na2CO3 and Mixed Na2CO3/Li2CO3 Particles: Influence of Li2CO3 on Phase Transitions of Na2CO3 and Formation of LiNaCO3.

The hygroscopic behaviors and phase changes of inorganic aerosols have been widely explored, but little is known on the hygroscopicity of soluble carbonates. The hydrated states of solid Na2CO3 particles in an air environment remain largely unclear. In this work, the hygroscopic growth, hydrated form transformations, and influence of internal Li2CO3 on phase transitions of Na2CO3 particles are investigated in linear and pulsed relative humidity (RH) changing modes by the vacuum Fourier transform infrared (FTIR) technique. For pure Na2CO3, aqueous droplets effloresced to a mixture of anhydrous Na2CO3 and Na2CO3·H2O with the initial efflorescence relative humidity (ERH) of 50.8%, probably concerning the formation of Na2CO3·10H2O in the conversion from aqueous to anhydrous Na2CO3. A reverse process is presented during the three-stage deliquescence transition beginning at ∼60.1% RH; i.e., anhydrous Na2CO3 transforms into aqueous Na2CO3 and Na2CO3·10H2O in stage I, Na2CO3·10H2O dissolves to aqueous Na2CO3 in stage II, and Na2CO3·H2O dissolves into aqueous Na2CO3 in stage III. For internally mixed Na2CO3/Li2CO3 particles, a double salt, LiNaCO3, is found in mixed crystalline phases for the first time, leading to the eutonic composition with Na2CO3. The experimental observations point to the excess of LiNaCO3 and complete consumption of Na2CO3 in eutonic composition formation, which results in the absence of Na2CO3 hydrates during phase transitions. The results provide key data for model simulations of hygroscopic properties and phase transitions of Na2CO3 as well as mixed soluble carbonates.

Mukonal Inhibits Cell Proliferation, Alters Mitochondrial Membrane Potential and Induces Apoptosis and Autophagy in Human CNE1 Nasopharyngeal Carcinoma Cells.

BACKGROUND Nasopharyngeal carcinoma results in high patient morbidity and mortality, due to early metastasis, and toxicity due to chemotherapy. Mukonal is plant-derived carbazole alkaloid that has been used in traditional Chinese medicine to treat several types of cancer. This study aimed to investigate the effects of mukonal on cell proliferation, apoptosis, autophagy, and the mitochondrial membrane potential of nasopharyngeal carcinoma cells in vitro. MATERIAL AND METHODS CNE1 human nasopharyngeal carcinoma cells and NP69 normal nasopharyngeal epithelial cells were cultured with and without treatment with increasing doses of mukonal. Cell viability was determined by the MTT assay. Fluorescence microscopy was used to detect reactive oxygen species (ROS), mitochondrial membrane potential, and the release of cytochrome C. Flow cytometry was used to examine changes in the cell cycle, electron microscopy examined cell autophagy, and Western blot was performed to measure levels of proteins associated with autophagy and apoptosis. RESULTS Mukonal had an antiproliferative effect on CNE1 cells, with an IC50 of 9 µM and there were effects of toxicity on normal NP69 cells. Mukonal triggered ROS-mediated changes in mitochondrial membrane potential which was also accompanied by the discharge of cytochrome C in the CNE1 cells. Mukonal activated autophagy and apoptosis in CNE1 cells, which was also associated with upregulation of the autophagy-related proteins, LC3 II and beclin-1, as well as apoptosis-associated proteins, Bax, cleaved caspase-3 and -9. Mukonal treatment also resulted in CNE1 cells cycle arrest at G2/M. CONCLUSIONS Mukonal inhibited the growth of human CNE1 nasopharyngeal carcinoma cells in vitro.

Template-Assisted Hydrothermal Growth of One-Dimensional Zinc Oxide Nanowires for Photocatalytic Application.

One-dimensional (1D) semiconductor ZnO nanowires have been successfully synthesized by a novel soft-chemical hydrothermal method with allylpolyethoxy amino carboxylate (AA-APEA) at low temperature. Their structure and properties have been characterized by a series of techniques, including X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and transmission electron microscopy (TEM). It was found that ZnO nanowires with diameters around 50 nm and lengths up to about several micrometers are well-distributed. The photocatalytic activity toward degradation of methylene blue (MB) aqueous solution under ultraviolet (UV) was investigated and the results showed that the ZnO nanowires exhibit a markedly higher photoactivity compared to the ZnO nanoparticles which were obtained without AA-APEA polymer assistant, and it can be ascribed to the special 1D morphology of the ZnO nanowires. In particular, the rate of degradation of the ZnO nanowires was 11 times faster than that of ZnO nanoparticles. In addition, the ZnO nanowires could be easily recycled in UV photocatalytic activity. These observations could promote new applications of photocatalyst for wastewater treatment utilizing oxide semiconductor nanostructures.

Three-Dimensional Simulation of Land Drains as a Preferential Pathway for Vapor Intrusion into Buildings.

Preferential pathways can be significant vapor intrusion (VI) contributors, causing potentially higher inhalation risk to residents of affected buildings than that arising through traditional intrusion pathways. To assess land drains as a preferential pathway, a three-dimensional model, validated using data from a 4-yr field study, was used to study the roles of subfoundation soil permeability on soil gas flow and indoor depressurization. Results indicated that it is almost impossible for an indirect preferential pathway like a land drain ending in subfoundation soils with a permeability <10 m to affect indoor air quality if the land drain connects to a source with the same vapor concentration as that of the groundwater source beneath the building. An equation was developed to estimate the threshold permeability. We also found that even after the preferential pathway was identified using indoor depressurization (also known as controlled pressure method [CPM]) and then turned off, the influence of the preferential pathway and indoor depressurization on indoor concentration might last for months, although it may not be significant (i.e., may not exceed one order of magnitude, in this study). In the absence of such a preferential VI pathway, CPM may actually reduce indoor air concentrations of contaminants below those present under natural indoor pressure conditions, due to the emission rate limit determined by the upward diffusion rate from the vapor source. Our study highlights the role of measuring subfoundation soil permeability to soil gas flow in site investigations and warns practitioners about the possible mischaracterization of indoor air concentration after applying CPM in the absence of a preferential pathway.

Engineering High-Performance Composite Cellulose Materials for Fast Hemostasis.

The development of an effective hemostatic agents is of vital importance for saving wounded individuals from uncontrolled hemorrhage, which is the main reason for preventable death after accidental injury. However, current high-performance hemostatic agents suffer from a cumbersome preparation procedures and poor biocompatibility. Here, we engineered a cellulosic-derived aerogel material by simply controlling the drying process of cellulose regeneration for fast hemostasis. Four different freeze-drying pretreatments were investigated. As compared with the other three, the cellulosic aerogel material prepared without freezing pretreatment exhibited the lowest crystallinity (21.3%) and the highest body fluid absorption capacity (20.3 times that of its own weight) due to its super hierarchical porous structure, which led to an excellent hemostatic performance in vitro blood coagulation (≈100 s). Moreover, the addition of gelatin and diatomite in the material could tune the functional groups and electrostatic properties of the aerogel and further enhance its hemostatic performance. Various characterizations, including X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), X-ray nanocomputed tomography (CT), scanning electron microscopy (SEM), and zeta potential analysis, were carried out to probe the structure-function relationship of the prepared material, and its mechanism of fast hemostasis was thereafter revealed. The results indicate that the developed aerogel is a cost-effective and feasibly scalable hemostatic material suitable for practical use in industry.

Biomethane enhancement from corn straw using anaerobic digestion by-products as pretreatment agents: A highly effective and green strategy.

The development of biogas projects feed by lignocellulosic biomass has been constrained by the high cost of pre- and post-treatment. In this study, a novel strategy for pretreatment by using two by-products, i.e., CO2 and liquid digestate (LD), generated from anaerobic digestion (AD) was developed to overcome these shortcomings. Results showed that corn straw pretreated in LD pressurized under 1 Mpa CO2 at 55 â„ƒ resulted in increased glucose and xylose contents and a 9.80% decrease in cellulose crystallinity. After 45 days of AD conversion, the methane yield increased by 50.97% compared with untreated straw. However, pretreatment in LD pressurized under 1 Mpa CO2 at 170 â„ƒ produced 5-hydroxymethylfurfural and furfural, which led to a decrease in methane production from the straw in the subsequent AD conversion. The alteration of the microbial community in the pretreated slurry at 55 °C was another potential contributor to the enhanced performance of AD.

A novel mechanocatalytical reaction system driven by fluid shear force for the mild and rapid pretreatment of lignocellulosic biomass.

Pretreatment is the initial stage of lignocellulosic biorefinery process, but is limited by the time-consuming processes, harsh conditions and/or undesirable products. Herein, a mild (<60 °C) and highly efficient pretreatment strategy is developed. The novel mechanocatalytical reaction system driven by fluid shear force helps to exfoliate cellulose from lignocellulose, and the heat generated by the shear process can be used to precipitate and recover the dissolved cellulose from the precooled NaOH/urea solution. The regenerated cellulose shows satisfying crystal structure (cellulose II), significantly decreased crystallinity and nearly tripled enzymolysis glucose yield. Almost 90% of lignin and hemicellulose could be rapidly separated. The separated lignin shows a nearly native structure with 64% ß-O-4 linkage, which is even higher than the ball-milling lignin (60%). This research provides a theoretical guidance for the mild pretreatment of lignocellulosic biomass, which will push the application of mechanocatalytical reaction system in biorefinery processes on a large scale.

Photo-Fenton superwettable NiFe2O4/TA/PVDF composite membrane for organic pollutant degradation with successively oil-in-water separation.

With regard to the treatment of multicomponent wastewaters, to construct multifunctional super-wetting membranes is highly attractive in current decade. In this work, a low-cost and novel NiFe2O4/TA/PVDF composite membrane was fabricated via a facile in-situ deposition method under vacuum system. In which, photo-response NiFe2O4 nanoparticles were immobilized on the surface of flexible PVDF base membrane via hydrophilic tannic acid (TA) as the binder. The resulting composite membrane exhibited a special superwettability of superamphilicity in air and underwater superoleophobicity with a nanoscale rough surface structure. One the one hand, NiFe2O4/TA/PVDF membrane can be used a reusable catalyst in Photo-Fenton degradation of organic dyes with high efficiency. On the other hand, the composite membrane can effectively separate emulsified oils from representative oil-in-water emulsions with excellent separation efficiency all above 99 % and relatively high flux (880-1525 Lm-2h-1 bar-1). More importantly, NiFe2O4/TA/PVDF composite membrane showed satisfactory processing efficiency, anti-fouling property and excellent reusability in deal with the mixed organic pollutants (water-insoluble emulsified oils and water-soluble organic dyes) existed in one aqueous system, which followed the procedure of initially photo-Fenton degradation of organic dyes emulsion and successively separation the remaining emulsion over the recovered membrane. This successful development of high-performance NiFe2O4/TA/PVDF composite membrane will provide a new candidate for both oil/water separation and organic wastewater treatment, as well as promote the utilization of spinel ferrites in the construction of multifunctional membrane for environmental purification.

Natural variation of DROT1 confers drought adaptation in upland rice.

Upland rice is a distinct ecotype that grows in aerobic environments and tolerates drought stress. However, the genetic basis of its drought resistance is unclear. Here, using an integrative approach combining a genome-wide association study with analyses of introgression lines and transcriptomic profiles, we identify a gene, DROUGHT1 (DROT1), encoding a COBRA-like protein that confers drought resistance in rice. DROT1 is specifically expressed in vascular bundles and is directly repressed by ERF3 and activated by ERF71, both drought-responsive transcription factors. DROT1 improves drought resistance by adjusting cell wall structure by increasing cellulose content and maintaining cellulose crystallinity. A C-to-T single-nucleotide variation in the promoter increases DROT1 expression and drought resistance in upland rice. The potential elite haplotype of DROT1 in upland rice could originate in wild rice (O. rufipogon) and may be beneficial for breeding upland rice varieties.

A review of efflorescence kinetics studies on atmospherically relevant particles.

The efflorescence transitions of aerosol particles have been intensively investigated due to their critical impacts on global climate and atmospheric chemistry. In the present study, we present a critical review of efflorescence kinetics focusing on three key issues: the efflorescence relative humidity (ERH) and the influence factors for aerosol ERH (e.g. particle sizes, and temperature); efflorescence processes of mixed aerosols, concerning the effect of coexisting inorganic and organic components on the efflorescence of inorganic salts; homogeneous and heterogeneous nucleation rates of pure and mixed aerosols. Among the previous studies, there are significant discrepancies for measured aerosol ERH under even the same conditions. Moreover, the interactions between organic and inorganic components remain largely unclear, causing efflorescence transition behaviours and chemical composition evolutions of certain mixed systems to be debatable. Thus, it is important to better understand efflorescence to gain insights into the physicochemical properties and characterize observed efflorescence characteristics of atmospheric particles, as well as guide further studies on aerosol hygroscopicity and reactivity.

Subsecond measurement on deliquescence kinetics of aerosol particles: Observation of partial dissolution and calculation of dissolution rates.

The deliquescence behavior of atmospheric aerosols has significant effects on global climate and atmospheric heterogeneous chemistry but remains largely unclear. The deliquescence kinetics data of micron-sized particles are scarce owing to the difficulty on performing the time-resolved dissolution measurements. In view of this technique bottleneck, an applicable and powerful experimental technique, i. e., vacuum FTIR combining pulsed relative humidity (RH) change technique, is introduced for gaining deliquescence kinetics information of three inorganic salts. For NaCl and (NH4)2SO4 aerosols, a solid-liquid mixing state derived from partial dissolution of NaCl and (NH4)2SO4 crystals is present during deliquescence, and the recrystallization will occur once RH decreases. While for NaNO3 particles, the recrystallization cannot occur as RH decreases owing to the formed amorphous NaNO3 solids after dying. The dissolution rates of NaCl, (NH4)2SO4 and NaNO3 solid particles are calculated, as a first attempt, by the upward pulsed RH mode. The measured rates show a significant dependency on ambient RH with three orders of magnitude. For NaCl particles, the measured J values range from 1.41 × 10-4 to 7.67 × 10-1 s-1 at RH of 73.41-75.15%. The J for (NH4)2SO4 particles is 7.34 × 10-3 to 2.46 × 100 s-1 over the RH range of 77.27%-80.13%. The J values for amorphous NaNO3 solids range from 6.01 × 10-3 to 2.63 × 100 s-1 as RH increases from 71.15% to 73.84%. Our results fill in the dataset of atmospheric models describing the kinetics features of deliquescence and provide an insight into dynamic solid-solution transition for PM2.5 particles.

Bifunctional NiAlFe LDH-coated membrane for oil-in-water emulsion separation and photocatalytic degradation of antibiotic.

A new NiAlFe layered double hydroxide/polydopamine/polyvinylidene fluoride (NiAlFe LDH/PDA/PVDF) membrane was fabricated by in-situ growth of LDH on the PDA modified PVDF membrane. The as-prepared membrane possesses a nano/microscale rough structural surface and displays the superior wettability of superhydrophilicity in air and underwater superoleophobicity. Combining the favourable features of superwettability and hierarchical rough structure, the NiAlFe LDH/PDA/PVDF membrane could effectively separate a series of oil-in-water emulsions with high efficiency (>99%) and high permeation flux (925-1913 L m-2 h-1 bar-1). Besides, owing to the light harvest ability of NiAlFe LDH, the relevant membrane also can be applied as a photocatalysis paper for the light-driven treatment of antibiotic residue in aqueous solution. In which, NiAlFe LDH/PDA/PVDF membrane can effectively degrade typical antibiotic tetracycline within 20 min under UV light irradiation, exhibiting excellent photocatalytic activity. In addition, cyclic experiments demonstrate that NiAlFe LDH/PDA/PVDF membrane has excellent stability and reusability both in oil-in-water emulsion separation and photocatalytic reaction. In general, the findings of this research demonstrate that photo-response LDH modified membranes have potential multiple applications in wastewater treatment.

Enhancing Hydrogen Productivity of Photosynthetic Bacteria from the Formulated Carbon Source by Mixing Xylose with Glucose.

To develop an efficient photofermentative process capable of higher rate biohydrogen production using carbon components of lignocellulosic hydrolysate, a desired carbon substrate by mixing xylose with glucose was formulated. Effects of crucial process parameters affecting cellular biochemical reaction of hydrogen by photosynthetic bacteria (PSB), i.e., variation in initial concentration of total carbon, glucose content in initial carbon substrate, and light intensity, were experimentally investigated using response surface methodology (RSM) with a Box-Behnken design (BBD). Hydrogen production rate (HPR) in the maximum value of 30.6 mL h-1 L-1 was attained under conditions of 39 mM initial concentration of total carbon, 59% (mol/mol) glucose content in initial carbon substrate, and 12.6 W m-2 light intensity at light wavelength of 590 nm. Synergic effects of metabolizing such a well-formulated carbon substrate for sustaining the active microbial synthesis to sufficiently accumulate biomass in bioreactor, as well as stimulating enzyme activity of nitrogenase for the higher rate biohydrogen production, were attributed to this carbon substrate that can enable PSB to maintain the relatively consistent microenvironment in suitable culture pH condition during the optimized photofermentative process.

Synthesis of Porphyrin Zr-MOFs for the Adsorption and Photodegradation of Antibiotics under Visible Light.

The release of antibiotics into the water environment can pose a serious threat to human and ecological health, so it is of great significance to effectively remove antibiotics from wastewater. In this work, porphyrinic zirconium metal-organic framework material, PCN-224, was first explored for the adsorption removal of antibiotics from water using tetracycline (TC) and ciprofloxacin (CIP) as examples. We prepared a series of PCN-224 with different particle sizes (150 nm, 300 nm, 500 nm, and 6 µm). Benefiting from the huge surface area (1616 m2 g-1), the 300 nm-PCN-224 sample had the best adsorption properties for TC and CIP. Remarkably, it exhibits fast removal rates and high adsorption capacities of 354.81 and 207.16 mg g-1 for TC and CIP, respectively. The adsorption of TC and CIP in 300 nm-PCN-224 is consistent with the pseudo-second-order kinetic model and Langmuir isotherm model, which indicates that the adsorption can be regarded as homogeneous monolayer chemisorption, and the adsorption is exothermic, which has been confirmed by thermodynamic studies. Under visible-light irradiation, 300 nm-PCN-224 exhibited high photocatalytic activity for TC and CIP. The adsorption studies confirmed that the adsorption of adsorbates takes place via the formation of hydrogen bonding, π-π interactions, and electrostatic attraction. In addition, the adsorbent can be simply regenerated by photocatalysis under visible light, and the adsorption-desorption efficiency is still above 85% after repeated use five times. The work of MOFs to remove antibiotics from water shows that MOFs have great potential in this field and are worthy of further study.

Microwave Solvothermal Synthesis of Three-Dimensional Bi2MoO6 Microspheres with Enhanced Photocatalytic Activity.

In this study, three-dimensional (3D) Bi2MoO6 microspheres were successfully fabricated by a facile, rapid, and mild microwave solvothermal strategy for the first time. The resultant 3D Bi2MoO6 microspheres exhibited superior adsorption capacity and photocatalytic efficiency in the degradation of the representative antibiotic ciprofloxacin under visible light, for which the reaction kinetic rate constant is 7.5 times as high as that of the as-synthesized zero-dimensional Bi2MoO6 nanoparticles. The 3D hierarchical porous structure and the high Brunauer-Emmett-Teller surface area providing abundant reactive sites mainly contributed to the enhanced photocatalytic activity. The results highlight the feasibility of 3D Bi2MoO6 microspheres as an efficient visible-light-responsive photocatalyst for antibiotic removal in an aqueous system.