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Achieving highly selective separation of organic mixtures is crucial to modern fine chemicals and pharmaceutical industries. The membrane-based organic solvent reverse osmosis (OSRO) technology is expected to break through this barrier. The key to achieving the separation of organic mixed liquids is to design the OSRO membrane as needed based on the physical and chemical properties of the target separation solvent. However, this poses a huge challenge to traditional OSRO membranes. In this work, we report composite polyamide (PA) OSRO membranes with ultrahigh polar/non-polar organic mixture selectivity. The surface polarity of the composite PA membrane is increased by coating a layer of Fe3+/tannic acid (Fe3+/TA) layer on the surface of the PA membrane. The enhanced surface polarity increases the interaction difference between polar and non-polar solvents and the membrane. And a polarization layer is formed on the membrane surface, which weakens the concentration polarization effect on the membrane surface. Under high-concentration feed liquid (the mass ratio of methanol/hexane is 7:3), the separation factor of the prepared membrane reaches 218, which is the highest value of all OSRO membranes reported so far. For the first time, we establish a partial flux analysis for the OSRO process. This analysis unravels the pressure, concentration dependence, and sensitivity of separation performance. It provides novel insights into the design of high-performance OSRO membranes. [Display omitted] • High-performance OSRO PA membrane prepared by Fe3+/TA surface modification. • Fe3+/TA coating enhances the surface polarity of PA membrane. • Enhanced surface polarity affects membrane-solvent interactions. • PA-Fe3+/TA membranes show ultrahigh separation factor for methanol/hexane mixture. • Established partial flux analysis to gain in-depth understanding of OSRO process. [ABSTRACT FROM AUTHOR]

Membrane separation technology has shown great potential in resource recovery, energy utilization, and environmental protection, attracting extensive attention for the various practical applications. The alginate-based hydrogel membrane, derived from natural biomass, possesses sustainability and anti-fouling properties, effectively reducing the burden of waste membrane disposal. However, the limitations of alginate hydrogel include its high swelling ability, low permeability, and poor mechanical properties. In this study, we propose a straightforward method to fabricate orderliness hydrogels by employing lanthanide ion via dual cross-linking with CaAlg, resulting in the formation of lanthanum calcium alginate (La-CaAlg) hydrogel membrane. The La-CaAlg membrane exhibits superior mechanical performance and anti-swelling properties compared to LaAlg and CaAlg membranes. Additionally, through small-angle scattering and low-field nuclear magnetic resonance studies on the membrane's spatial orientation, and pore size distribution, we gained the comparable results into its internal structure for the design insight. Notably, the La-CaAlg membrane demonstrates outstanding performance in dye/salt separation, showcasing high selectivity and permeability. We propose the strategy that enhances the orderliness and durability of the alginate hydrogel membrane, providing the separation design insight to overcome the limitations associated with the permeability and rejection trade-off. [Display omitted] • The dual cross-linking strategy was proposed to adjust the structural orderliness. • La-CaAlg membrane exhibits excellent mechanical stability, anti-fouling characteristic, and anti-swelling properties. • La-CaAlg membrane offers valuable insights to overcome the limitations associated with the trade-off between permeability and rejection. • La-CaAlg membrane has outstanding dye/salt selectivity separation property. [ABSTRACT FROM AUTHOR]

[Display omitted] • GO @ PTCDA-UiO-66-NH 2 membrane was prepared by self-assembly of Π-Π conjugation of the large planar benzene ring. • Synergy of GO, PTCDA and UiO-66-NH 2 created a unique vertical-horizontal filtration system to improve the separation performance. • The membrane maintained good filtration performance under high salt concentration and extreme pH environment. • The membrane had good structural stability and good cycle performance. A new type of composite membrane was prepared through the vacuum filtration self-assembly, in which, graphene oxide (GO) was the basic material, and the horizontal insertion material is product of perylene-3, 4, 9, 10-tetracarboxylic dianhydride (PTCDA) and UiO-66-NH 2 (PTCDA-UiO-66-NH 2). The leading role of Π-Π conjugate, auxiliary effect of hydrogen bonding during membrane preparation have been confirmed through Fourier transform infrared spectroscopy (FTIR), UV–visible spectrophotometer, Raman spectroscopy, and X-ray diffraction (XRD). The prepared GO@PTCDA-UiO-66-NH 2 membrane had new nodular structure compared to GO membrane by scanning electron microscopy (SEM) and atomic force microscopy (AFM), which promoted the water transport. In addition, the insertion of PTCDA-UiO-66-NH 2 narrowed the actual filtration spacing between GO sheets, and PTCDA-UiO-66-NH 2 could also adsorbed dye laterally. Experiments showed that the permeance of GO@PTCDA-UiO-66-NH 2 membrane was 1.7 times of GO membrane, and the removal of methyl blue, congo red, crystal violet and disperse black 9 was close to 100%. Under extreme pH, high salt concentration and multiple recycling, its separation ability was still excellent. The GO@PTCDA-UiO-66-NH 2 membrane constituted a unique synergistic structure of vertical-screening and horizontal-adsorption, which successfully overcame the trade-off effect and obtained excellent stability of structure and performance. Therefore, GO@PTCDA-UiO-66-NH 2 membrane had great potential in practical applications. [ABSTRACT FROM AUTHOR]

The relationship between the rigidity, microporosity and the ideal gas separation properties of polymers of intrinsic microporosity (PIM) is very important but seldom studied in detail. Herein, we designed a novel bromine substituted intrinsic microporosity polyimide (PIM-DB-PI), and compared its gas separation properties with a more rigid and microporous PIM-PI-1 (680 vs 435 m2 g−1) from −30 to 30 °C for the first time. Both PIM-PIs showed improved ideal gas separation properties with their performance for H 2 /N 2 , O 2 /N 2 , CO 2 /N 2 and CO 2 /CH 4 changed from well below the 2008 trade-off lines to approach or even above their latest trade-off lines upon decreasing temperature. The PIM-PI-1 with higher microporosity and rigidity showed higher gas permeability, diffusion and solubility coefficients as well as larger activation energy of permeation (E p) and diffusion (E d) than PIM-DB-PI, whereas PIM-DB-PI exhibited higher gas pair selectivity derived from its larger diffusion selectivity (a D), which was attributed to its higher enthalpic selectivity. Besides, the PIM-DB-PI showed a much larger critical penetrate size ((f/c) 1/2 ) than PIM-PI-1 due to its higher flexibility. The above finding indicates that both rigidity and microporosity are very important in fine-tuning the gas transport through the polymer membrane. The microporosity has dominant effect on the gas diffusion selectivity of the membrane and the rigidity has more effect on the critical diffusion penetrate size ((f/c) 1/2 ) of PIM-PI membranes. [Display omitted] • Gas separation properties of two PIM-PIs were reported from 30 to −30 °C. • PIM-PI-1 with higher surface area and rigidity showed larger permeability and lower selectivity than PIM-DB-PI. • The PIM-PI-1 showed higher activation energy of permeation and diffusion than PIM-DB-PI. • The microporosity had much stronger effect than rigidity on the diffusion selectivity due to higher enthalpic selectivity. • The rigidity is dominant in determine the critical diffusion penetrate size ((f/c) 1/2 ) of the PIM-PI membranes. [ABSTRACT FROM AUTHOR]

• The stability of graphene oxide/methylene blue (GO/MB) membrane was enhanced obviously. • An effective strategy to prepare GO/MB membrane with outstanding separation performance. • The effect of various factors on dyes rejection was summarized, which had far-reaching significance in wastewater treatment. • Molecular dynamics simulations were utilized to trace nanoscale events occurring over interfacial behaviors. To improve the stability and rejection for dyes of graphene oxide (GO) membrane, we employed methylene blue (MB) as a modifier to prepare GO/MB composite membrane through vacuum filtration. The rejection of GO/MB membrane for different dyes (methyl orange, disperse black 9 and rhodamine B) reached 93.32%, 99.85% and 82.56%, respectively, and the pure water flux was 7.67 L⋅m−2⋅h−1, indicating that GO/MB composite membranes have good application prospects. The interaction mechanism between GO and MB was described in detail. Moreover, the united-atomic models for molecular dynamics (MD) simulation was performed, through which we can trace the nanoscale events occurring over the interfacial behaviors and provided molecular information at nanoscale interfaces for our study. The effects of the interaction between dye molecules and composite membrane, charges of the dyes, molecular weight and molecular structure of dyes on nanofiltration performance were also discussed, which laid foundation of the research in field of water treatment. [ABSTRACT FROM AUTHOR]

The development of membranes for protein purification has stringent requirement of disinfection resistance, low protein adsorption and anti-fouling, without changing protein structure. In this study, hydrophilic titanium dioxide (TiO 2)/calcium alginate (TiO 2 /CaAlg) hydrogel membranes were prepared by a simple ionic cross-linking method. The effects of the porogenic agent polyethylene glycol (PEG) concentration, the molecular weight of PEG, and the concentration of TiO 2 on the filtration properties were systematically investigated. The TiO 2 /CaAlg membrane exhibited excellent bovine serum albumin (BSA) rejection and anti-fouling properties. The mechanical properties and surface energy of the TiO 2 /CaAlg membrane were significantly improved. The chemical bonding mechanism of TiO 2 and NaAlg was investigated by molecular dynamic simulation. The TiO 2 /CaAlg membrane had good chlorine resistance and could be disinfected or cleaned with sodium hypochlorite. The TiO 2 /CaAlg hydrogel membrane loaded with polyhydroxybutyrate (PHB) nanofibers maintained high flux (136.7 L/m2h) and high BSA rejection (98.0 %) at 0.1 MPa. The results of circular dichroism and synchronous fluorescence indicated that the secondary structure of BSA was maintained after membrane separation. This study provides one method for the preparation of green and environmentally friendly membrane for protein purification. [Display omitted] • TiO 2 /CaAlg membrane exhibited good anti-fouling property and chlorine resistance. • Interaction mechanism of TiO 2 and NaAlg was investigated by MD simulation. • Surface energy of TiO 2 /CaAlg was 23 times higher than that of CaAlg, which reduced protein adsorption. • TiO 2 /CaAlg-PHB was used for BSA purification and the flux was 136.7 L·m−2·h−1 at 0.1 MPa. • Structure of BSA could be maintained after membrane separation. [ABSTRACT FROM AUTHOR]

To improve the selectivity of nanofiltration membranes (NFMs) for multi/monovalent anions, including SO 4 2−/Cl−, a strategy to moderately amplify the pore size while maintaining chargeability of the membranes was proposed. Four diamine monomers based on piperazine ring, with reaction site distance increased from 2.8 Å to 5.1 Å, were adopted and the effect of the monomer structure especially the reaction site distance on the structure and performance of the NFMs was studied. Position annihilation spectroscopy and molecular dynamics simulation were adopted to provide thorough characterization of the separation layer of the NFMs. The results showed that NFMs prepared by monomers with moderately increased reaction site distance displayed a moderately amplified pore size, which could facilitate the penetration of Cl− and thus improve SO 4 2−/Cl− separation ability. The Na 2 SO 4 /NaCl selectivity got 10.0 with water permeability up to 18.5 L m−2 h−1 bar−1, exceeding the upper-bound of permeation flux and Na 2 SO 4 /NaCl selectivity of membranes prepared by traditional interfacial polymerization. [Display omitted] • The reaction site distance of diamine monomers was finely tuned. • The effect of the reaction site distance on the structure of NFMs was studied. • NFMs with moderately amplified pore size was obtained. • NFMs showed improved Na 2 SO 4 /NaCl sieving capability exceeding the upper-bound line. [ABSTRACT FROM AUTHOR]

Highly efficient hydrogen separation membrane is critical in the future hydrogen powered zero carbon society. However, challenges left in searching for hydrogen separation membranes with high permeability, selectivity and easy accessibility. Here, this target was partially achieved by a series of membranes made from in-situ ozone oxidized intrinsic mciroporous polymer membranes (O 3 -PIMs) within minutes. The FT-IR spectra and XPS results suggested that C O and OH groups were formed after the oxidation reaction. The TGA and EDS mapping results indicated that the oxidation reaction happened only on the skin surface of PIM-1 membrane within 10 μm in depth. After O 3 oxidation, the O 3 -PIMs showed a large drop in gas permeability whereas huge increases in gas pair selectivity, resulting in large improved overall performance for H 2 /N 2 , H 2 /CH 4 and H 2 /CO 2 that beat the latest trade-off lines. The O 3 -PIM-60 showed a H 2 permeability of 1294 Barrer and H 2 /N 2 , H 2 /CH 4 and H 2 /CO 2 selectivity of 93.7, 121, and 2.92, respectively. The increased selectivity of O 3 -PIMs is due to their remarkably enhanced size sieving effect induced enhanced diffusion selectivity. Theoretical simulation showed that this is caused by the O 3 reaction induced pore blocking effect that shifted the mciropore of PIM-1 to the ultra-micropore region, and thus, significantly improved the hydrogen sieving efficiency. In all, this facile and highly efficient ozone oxidation method provides a great perspective in searching for high performance hydrogen separation membranes. [Display omitted] • O 3 -PIMs was obtained by in-situ ozone oxidation of PIM-1 for the first time. • This method is simple, controllable and highly efficient. • The O 3 oxidation happened at the surface within 10 μm in depth. • The performance improvement originated from the enhanced diffusion selectivity. • O 3 -PIM-60 membrane exceed the 2015 Robeson upper bounds for H 2 /N 2 and H 2 /CH 4. [ABSTRACT FROM AUTHOR]

To improve the mechanical strength, antimicrobial and anti-swelling ability of calcium alginate hydrogel membrane, the graphene oxide/calcium alginate hybrid (GCA-H) hydrogel filtration membrane was prepared by ion cross-linking without organic solvent in this study. Meanwhile, the morphology, structure, and chemical bonding mechanism of membranes were characterized. Furthermore, we also investigated the mechanical strength, swelling behaviors, anti-bacterial, and anti-fouling properties of the GCA-H membrane. Since the excellent hydrophilicity, the GCA-H membrane showed high flux recovery rate (>97 %) based on the alternating filtration tests without cleaning the membrane. It was mentioned that the maximum stress-strain of the GCA-H membrane could reach 1.53 MPa, which was 2.34-fold more than that of the unmodified membrane. Due to the enhanced structure, it was beneficial to design the thinner membrane for further application. Moreover, we evaluated the impact of the operating parameters on dye/salt separation performance in this work. Generally, the rejections of Coomassie brilliant blue (CBB) and NaCl of GCA-H membrane were approximately 99 % and 8 %, respectively. Finally, we summarized the separation factor and nominalized flux for the dye/salt separation. The GCA-H membrane still maintained a good separation efficiency after being placed for 45 days. So the GCA-H membrane has a great potential in the selectivity separation process, which may provide a sustainable strategy for dye recycle. Graphene oxide/calcium alginate hybrid hydrogel (GCA-H) membrane was prepared by ion-crosslinking and applied for the separation of dye/salt. The GCA-H membrane exhibited high selectivity for salt and dye and the selectivity coefficient was 230.5. The GCA-H membrane showed high antimicrobial property. [Display omitted] • A graphene oxide/calcium alginate hybrid (GCA-H) hydrogel filtration membrane was fabricated in water. • The chemical bonding mechanism of GO and NaAlg was investigated. • The GCA-H membrane has excellent antimicrobial and anti-fouling properties. • The selectivity coefficient of GCA-H membrane for dye/salt was 230.5. [ABSTRACT FROM AUTHOR]

Efficient separation of Mg2+ and Li + remains a major challenge in the extraction of lithium from salt lake brine. In this work, an electro-nanofiltration (NF) process was employed to separate Mg2+ and Li+ from the MgCl 2 /LiCl feed solution under a current density of 0–2.83 mA cm−2 and at an operating pressure of 5 bar. The surface chargeability of the NF membrane under an electric field (EF) was investigated in detail by combination of the experiment and theoretical simulation. It was found that Mg2+ ions were almost completely rejected (no Mg2+ detected by an ICP-OES with a determination limit of 0.01 ppm). A high permeance of Li+ (0.55 molm−2h−1) and a stable solution flux of 75 ± 2 Lm−2h−1 were achieved. The separation performance was far better than the results reported in the literature until now. It was believed that high positive charges on the negative-charged NF membrane surface were in-situ reconstructed and enhanced with the increase in current density due to the complexion and enrichment of Mg2+ on the membrane surface, leading to the high rejection for Mg2+. The dehydration of Li + ions with a low hydration energy under EF promoted the permeance of Li+. This work provides a practical route for efficient separation of Mg2+/Li+, and would have a huge potential in the extraction of high-pure Li+ salt from salt lakes. [Display omitted] • Electro-NF process was employed to efficiently separate of Mg2+ and Li+. • Almost 100% rejection for Mg2+ and high permeance for Li+ were simultaneously achieved. • High positive charges in-situ reconstructed on the NF membrane surface by EF contributed to high rejection for Mg2+. • Highly efficient and stable extraction of Li+ from the acidic feed solution was achieved. [ABSTRACT FROM AUTHOR]

[Display omitted] • Gold nanoparticles (Au NPs) modified graphene hydrogel (Au-RGOH) is synthesized for sensitive, selective and reversible NO 2 and NH 3 gas monitoring. • The Au-RGOH exhibits an order of magnitude higher sensitivity and much lower limit of detection than the unmodified RGOH. • An integrated microheater platform is exploited to enhance the immunity of NO 2 and NH 3 gas sensing to humidity. • The Au NPs decoration effect and temperature-assisted screening effect are understood by DFT and MD theoretical studies. A one-step, facile hydrothermal approach was developed to synthesize gold nanoparticles (Au NPs) modified reduced graphene oxide hydrogel (Au-RGOH) with three-dimensional (3D) porous microstructures for sensitive NO 2 and NH 3 monitoring. It was found that the Au-RGOH displayed an order of magnitude higher sensitivity and much lower limit of detections (LODs) than the unmodified RGOH counterpart, demonstrating the remarkable role of Au NPs in boosting the responsivity toward NO 2 and NH 3. To address the disturbance of humidity on gas sensing, an integrated microheater platform was exploited to quench the response to humidity without impairing the response to target gas, enhancing the resistance to humidity. The mechanisms of Au NPs decoration effect and temperature-assisted screening effect were elucidated by molecular dynamics and density functional theory simulations for the first time. It revealed that Au NPs were active adsorption sites for NO 2 molecules, and the strong and weak dependence of the adsorption of H 2 O and NO 2 molecules on temperature, respectively, providing theoretical evidences for experimental results. Benefiting from the chemical sensitization effect of Au NPs, 3D porous structure, and localized temperature modulation, the Au-RGOH gas sensor exhibited high sensitivity, low LODs (1.16 NO 2 and 55.3 ppb NH 3), excellent selectivity, reversibility, fast recovery speed, etc. This study offers a facile and practical solution to boost the gas sensing performance by engineering the surface, structure and operation temperature of transducing materials, as well as understand the sensing behaviors via theoretical simulations. [ABSTRACT FROM AUTHOR]

(a) MD simulation of pore structure (red: alginate matrix, white: membrane pore structure, blue: interface pore structure) and (b) pore size distribution of BaAlg hydrogel, (c) schematic diagrams of the molecule/ion separation process of BaAlg-PET membrane and (d) the selectivity for the separation of dye/NaCl of the membranes in this work and compared with other reported membranes. [Display omitted] • PET non-woven resisted the deformation of CaAlg hydrogel than PHB nanofibers and PP non-woven. • BaAlg-PET exhibited higher strength, flux and better separation performance than CaAlg-PET. • Membrane pore structure and pore size distribution of BaAlg hydrogel were generated via MD simulations. Calcium alginate (CaAlg) hydrogel has good anti-pollution performance. However, the self-supporting CaAlg hydrogel filtration membrane is difficult to be batch prepared due to its poor mechanical properties. In this paper, polyester (PET) non-woven fabric, polypropylene (PP) non-woven fabric and polyhydroxybutyrate (PHB) nanofibers were used as support layer to prepare CaAlg composite membranes. A series of studies proved that CaAlg-PET membrane showed higher stability and flux, which revealed that PET non-woven fabric was the best carrier among the three fiber carriers to enhance the various properties of hydrogel. Methyl blue (MB) and sodium chloride (NaCl) were used as the representatives of molecules and ions, respectively. The effects of concentration, operating pressure and temperature on the separation performance of MB/NaCl by CaAlg-PET membrane were investigated. The flux of CaAlg-PET membrane was 19.3 L·m−2·h−1·bar−1, and the membrane showed a high selectivity of 183.4 to MB/NaCl mixture (99.5% rejection of MB and 8.3% rejection of NaCl). Moreover, Barium ion was used to cross-link sodium alginate to prepare barium alginate (BaAlg) hydrogel coated composite membrane (BaAlg-PET) using PET fiber as the carrier. The BaAlg-PET membrane exhibited higher strength, stability, flux and better separation performance than CaAlg-PET membrane. BaAlg-PET membrane exhibited a high flux of above 35.5 L·m−2·h−1·bar−1, and the molecular ion selectivity was 306.3 (99.7% rejection of MB and 8.1% rejection of NaCl). Membrane pore structure and pore size distribution of BaAlg hydrogel membrane were generated by molecular dynamic (MD) simulations. In sum, this work provided a green, economical and expandable new idea and membrane material for the separation of molecules and ions. [ABSTRACT FROM AUTHOR]

[Display omitted] • PES/SPSf membrane was prepared via NIPS method using adipic acid as additive. • A sponge-like structure was formed due to the H-bonding between adipic acid & SPSf. • Hydration radius was estimated by MD simulations to reveal the rejection of dyes. • The membrane exhibited a higher dye rejection at low ionic strength. • High rejection of membrane for dyes was a synergy of size sieving and charge effect. Polyethersulphone (PES)/sulfonated polysulphone (SPSf) tight ultrafiltration (TUF) membrane was tailored for dye/salt selective separation via non-solvent induced phase separation (NIPS) method using adipic acid (AA) as a pore forming agent. Sucrose and PEG (200–1000 Da) as neutral model molecules and eight kinds of charged dye model molecules (269.3–960.8 Da) were employed to explore the roles of size sieving and charge effect during the membrane separation process. Results showed that the membrane obtained from the casting solution with the mass ratio of PES/SPSf = 84/16 and 11 wt% AA possessed a fully sponge-like structure with an average pore size of 1.8 nm and the molecular weight cut off (MWCO) of 7250 Da. The pure water permeance of the membrane was up to 72.2 L/m2 h bar and displayed a reasonable retention for the neutral molecules including PEG 1000 (46.0%), PEG 400 (19.7%) and sucrose (17.2%). Simultaneously, the membrane exhibited a higher rejection for dyes with the similar molecular weight (M w) such as methyl orange (MO) (69.4%), acid blue 25 (AB25) (92.6%) and Evans blue (EB) (100%). The high rejection for these dyes was mainly attributed to the synergy between the size sieving and charge effect. Furthermore, the rejection of membrane for methyl red (MR), MO and AB25 was 50.1%, 69.4% and 92.6%, respectively. Molecular dynamics (MD) simulations revealed that the hydration radius of AB25 (1.04 nm) was bigger than that of MR (0.94 nm) and MO (0.99 nm), leading to higher rejection illustrating that size sieving played an important role in the rejection of dyes (M w less than 696.7 Da) with the same charge. Specifically, the contribution rate of steric hindrance and charge effect to the dye rejection gradually decayed as an increase on the molecular weight of dyes (over 416.0 Da). In addition, the rejection of MR, MO, indigo carmine (IC) and acid fuchsin (AF) decreased with an increase in the ionic strength of feed solutions due to the shielding effect of space charge. In summary, our work provides a profound understanding of the membrane selective separation mechanism for dye wastewater treatment and reuse. [ABSTRACT FROM AUTHOR]

Sub-ambient temperature membrane-based separation is attracting more and more attention in solving the industrial energy intensive separation challenges. However, the research on low temperature gas separation properties of polymeric membranes is limited. Here, gas separation performance of an intrinsic microporous polymer (PIM-1) at temperatures of −30, −20, −10, 0, 10, and 30 °C were fully characterized for the first time. As the temperature decreases, there was a continuous drop in He, H 2 , N 2 , O 2 , CH 4 and CO 2 permeability coupled with a sharply increased ideal gas pair selectivity with the overall performance gradually outperformed the latest trade-off curves for H 2 /N 2 , O 2 /N 2 , CO 2 /CH 4 and CO 2 /N 2. In which, the O 2 and CO 2 permeability of PIM-1 at −30 °C reached as much as 159 and 1380 Barrer, combined with O 2 /N 2 and CO 2 /N 2 ideal selectivity of 9.35 and 81.2, respectively. The drop in permeability originated from the decresaed diffusion coefficients that overweigh the solubility increase, whereas the increased ideal selectivity was due to the enhanced ideal diffusion selectivity (a D), especially the energetic factor of the ideal diffusivity selectivity upon decreasing temperatures. The higher performance induced by low temperatures derived from the shrinkage of the micropore in PIM-1 to more size sieving ultra-micropore region. Additionally, an O 2 permeability of 157 Barrer and O 2 /N 2 selectivity of 8.0 for mixed-gas at −20 °C under upstream pressure of 16 bar was observed. The results indicate that PIM-1 operates at sub-ambient temperature has great perspective in gas separation applications. Image 1 • Sub-ambient temperatures gas separation properties of PIM-1 were evaluated. • The performance of PIM-1 increased significantly with decreasing temperatures. • PIM-1 showed an unprecedented O 2 permeability of 159 Barrer and O 2 /N 2 selectivity of 9.35 at −30 °C. • The performance improvement originated from the enhanced diffusion selectivity. • An extremely high O 2 /N 2 mixed-gas selectivity of 8 and O 2 permeability of 157 Barrer was observed at 16 Bar and −20 °C. [ABSTRACT FROM AUTHOR]

Sulfonated polysulfone (SPSf) and water as additives were employed to tailor the morphology and performance of polyethersulfone (PES) ultrafiltration (UF) membrane using non-solvent induced phase separation (NIPS) for the purposes of dye and salt selective separation. Results showed that the viscosity of PES/SPSf/DMAc casting solution (polymer concentration 28 wt%) sharply increased from 1900 to 2650 mPa s with the addition of H 2 O (7 wt%) owning to the formation of pregelation. It was also revealed that PES polymer chains solidified and shrank faster than SPSf polymer chains during NIPS process, leading to –SO 3 - groups of SPSf to cover the surface of PES/SPSf polymer matrix. The resultant PES/SPSf UF membrane possessed superior pure water permeance (110.4 L/m2 h bar) compared with the pristine PES membrane (0.13 L/m2 h bar). The improvement in water permeance was ascribed to the synergy of SPSf and water, which enhanced the surface pore size, top surface porosity and hydrophilicity of PES membrane. Meanwhile, molecular dynamic (MD) simulations revealed that H 2 O can weaken the interaction between PES and SPSf chains and slow down the mutual diffusion in favour of the movement and ordered arrangement of chains. Additionally, the rejection of Evans blue (EB), Coomassie brilliant blue (BBR), Congo red (CR) and Acid fuchsin (AF) dye solution (0.1 g/L) by PES/SPSf membrane were 99.0%, 99.9%, 99.2% and 90.1%, respectively, whereas Na 2 SO 4 rejection was less than 5%. In sum, this work supplies a simple avenue to tailor PES membrane with enhanced permeance as well as separation performance of dye/salt mixture. Image 1 • The synergistic effect between SPSf and H 2 O was proposed for the first time. • MD simulation verifies H 2 O can weaken the interaction between PES and SPSf chains. • PES shows a faster curing rate than SPSf which induces –SO 3 - covering the matrix. • Synergistic effect of SPSf & H 2 O raised pore size & hydrophilicity of PES membrane. • PES/SPSf membrane shows high permeability and selectivity for dye/salt separation. [ABSTRACT FROM AUTHOR]

• Ag nanoparticles and 6-Mercaptohexanoic acid co-modified reduced graphene oxide (RGO-Ag-MHA) is synthesized for ultrasensitive, selective and reversible NO 2 detection at room temperature. • The RGO-Ag-MHA exhibits orders of magnitude higher sensitivity and much lower limit of detection than the unmodified RGO. • The impacts of Ag NPs and MHA decorations on the NO 2 sensing properties are revealed by both DFT and MD theoretical studies. • The binding energy of NO 2 on Ag NPs and MHA is 2.03 and 10.9 times higher than that on RGO. Silver nanoparticles (NPs) and 6-Mercaptohexanoic acid (MHA) co-modified reduced graphene oxide (RGO-Ag-MHA) is rationally designed for ultrasensitive and highly reversible NO 2 sensing at room temperature (RT). Due to the enhanced adsorption of NO 2 on the abundant active sites provided by Ag NPs and MHA, both the NO 2 adsorption and charge transfer processes are promoted. Consequently, the RGO-Ag-MHA exhibits orders of magnitude higher sensitivity and much lower limit of detection (LOD) toward NO 2 than the unmodified RGO. These experimental observations are supported by theoretical simulations, as density functional theory simulation reveals that the binding energy of NO 2 on Ag NPs and MHA is 2.03 and 10.9 times higher than that on RGO, respectively. Furthermore, molecular dynamics simulation indicates the adsorbed NO 2 density on RGO-Ag-MHA is twofold higher than that on RGO. The RGO-Ag-MHA NO 2 sensor displays very competitive performance, including ultrahigh sensitivity (53 ppm-1), exceptional low theoretical LOD (3.5 ppb), excellent selectivity, linearity and repeatability. This work not only unveils the role of surface co-modification in dictating the chemical sensing performance of graphene, but also provides a feasible route to fabricate high-performance, RT NO 2 sensors for various applications. [ABSTRACT FROM AUTHOR]

Cluster aggregation states are thermodynamically favored at the subnanoscale, for which an inverse growth from nanoparticles to clusters may be realized on subnanometer supports. Herein, we develop Au-polyoxometalate-layered double hydroxide (Au-POM-LDH) sub-1 nm nanosheets (Sub-APL) based on the above strategy, where sub-1 nm Au clusters with negative valence are generated by the in situ disintegration of Au nanoparticles on POM-LDH supports. Sub-1 nm Au clusters with ultrahigh surface atom ratios exhibit remarkable efficiency for glutathione (GSH) depletion. The closely connected sub-1 nm Au with negative valence and POM hetero-units can promote the separation of hole-electrons, resulting in the enhanced reactive oxygen species (ROS) generation under ultrasound (US). Besides, the reversible redox of Mo in POM is able to deplete GSH and trigger chemodynamic therapy (CDT) simultaneously, further enhancing the oxidative stress. Consequently, the Sub-APL present 2-fold ROS generation under US and 7-fold GSH depletion compared to the discrete Au and POM-LDH mixture. Therefore, the serious imbalance of redox in the TME caused by the sharp increase of ROS and rapid decrease of GSH leads to death of tumor ultimately., (© 2024 Wiley-VCH GmbH.)

Aromatic amines are important commercial chemicals, but their carcinogenicity poses a threat to humans and other organisms, making their rapid quantitative detection increasingly urgent. Here, amorphous MoO 3 (a-MoO 3 ) monolayers with localized surface plasmon resonance (LSPR) effect in the visible region are designed for the trace detection of carcinogenic aromatic amine molecules. The hot-electron fast decay component of a-MoO 3 decreases from 301 fs to 150 fs after absorption with methyl orange (MO) molecules, indicating the plasmon-induced hot-electron transfer (PIHET) process from a-MoO 3 to MO. Therefore, a-MoO 3 monolayers present high SERS performance due to the synergistic effect of electromagnetic enhancement (EM) and PIHET, proposing the EM-PIHET synergistic mechanism in a-MoO 3 . In addition, a-MoO 3 possesses higher electron delocalization and electronic state density than crystal MoO 3 (c-MoO 3 ), which is conducive to the PIHET. The limit of detection (LOD) for o-aminoazotoluene (o-AAT) is 10 -9  M with good uniformity, acid resistance, and thermal stability. In this work, trace detection and identification of various carcinogenic aromatic amines based on a-MoO 3 monolayers is realized, which is of great significance for reducing cancer infection rates., (© 2024 Wiley-VCH GmbH.)

Solar-driven CO 2 reduction and water oxidation to liquid fuels represents a promising solution to alleviate energy crisis and climate issue, but it remains a great challenge for generating CH 3 OH and CH 3 CH 2 OH dominated by multi-electron transfer. Single-cluster catalysts with super electron acceptance, accurate molecular structure, customizable electronic structure and multiple adsorption sites, have led to greater potential in catalyzing various challenging reactions. However, accurately controlling the number and arrangement of clusters on functional supports still faces great challenge. Herein, we develop a facile electrosynthesis method to uniformly disperse Wells-Dawson- and Keggin-type polyoxometalates on TiO 2 nanotube arrays, resulting in a series of single-cluster functionalized catalysts P 2 M 18 O 62 @TiO 2 and PM 12 O 40 @TiO 2 (M=Mo or W). The single polyoxometalate cluster can be distinctly identified and serves as electronic sponge to accept electrons from excited TiO 2 for enhancing surface-hole concentration and promote water oxidation. Among these samples, P 2 Mo 18 O 62 @TiO 2 -1 exhibits the highest electron consumption rate of 1260 μmol g -1 for CO 2 -to-CH 3 OH conversion with H 2 O as the electron source, which is 11 times higher than that of isolated TiO 2 nanotube arrays. This work supplied a simple synthesis method to realize the single-dispersion of molecular cluster to enrich surface-reaching holes on TiO 2 , thereby facilitating water oxidation and CO 2 reduction., (© 2024 Wiley-VCH GmbH.)

The preparation of atom-thick porous lattice hosting Å-scale pores is attractive to achieve a large ion-ion selectivity in combination with a large ion flux. Graphene film is an ideal selective layer for this if high-precision pores can be incorporated, however, it is challenging to avoid larger non-selective pores at the tail-end of the pore size distribution which reduces ion-ion selectivity. Herein, we develop a strategy to overcome this challenge using an electrochemical repair strategy that successfully masks larger pores in large-area graphene. 10-nm-thick electropolymerized conjugated microporous polymer (CMP) layer is successfully deposited on graphene, thanks to a strong π-π interaction in these two materials. While the CMP layer itself is not selective, it effectively masks graphene pores, leading to a large Li + /Mg 2+ selectivity from zero-dimensional pores reaching 300 with a high Li + ion permeation rate surpassing the performance of reported materials for ion-ion separation. Overall, this scalable repair strategy enables the fabrication of monolayer graphene membranes with customizable pore sizes, limiting the contribution of nonselective pores, and offering graphene membranes a versatile platform for a broad spectrum of challenging separations., (© 2024. The Author(s).)

Two-dimensional (2D) materials have shown unique chemical and physical properties; however, their synthesis is highly dependent on the layered structure of building blocks. Herein, we developed monolayer Dy 2 O 3 -phosphomolybdic acid (PMA) nanosheets and nanotubes based on microwave synthesis. Microwave-assisted synthesis with high-energy input gives a faster and dynamically driven growth of nanomaterials, resulting in high-purity nanostructures with a narrow size distribution. The reaction times of the nanosheets and nanotubes under microwave synthesis are significantly reduced compared with oven-synthesis. Dy 2 O 3 -PMA nanosheets and nanotubes exhibit enhanced activity and stability in photoconductance, with higher sensitivities (0.308 μA cm -2 for nanosheets and 0.271 μA cm -2 for nanotubes) compared to the individual PMA (0.12 μA cm -2 ) and Dy 2 O 3 (0.025 μA cm -2 ) building blocks. This work demonstrates the promising application potential of microwave-synthesized 2D heterostructures in superconductors and photoelectronic devices.

Chirality evolution from molecule levels to the nanoscale in an achiral system is a fundamental issue that remains undiscovered. Here, we report the assembly of polyoxometalate (POM) clusters into chiral subnanostructures in achiral systems by programmable single-molecule interactions. Driven by the competing binding of Ca 2+ and surface ligands, POM assemblies would twist into helical nanobelts, nanorings, and nanotubes with tunable helicity. Chiral molecules can be used to differentiate the formation energies of chiral isomers and immobilize the homochiral isomer, where strong circular dichroism (CD) signals are obtained in both solutions and films. Chiral helical nanobelts can be used as circularly polarized light (CPL) photodetectors due to their distinct chiroptic responsivity for right and left CPL. By the fine-tuning of interactions at single-molecule levels, the morphology and CD spectra of helical assemblies can be precisely controlled, providing an atomic precision model for investigation of the structure-chirality relationship and chirality manipulation at the nanoscale.

Emerging organic contaminants in water matrices have challenged ecosystems and human health safety. Persulfate-based advanced oxidation processes (PS-AOPs) have attracted much attention as they address potential water purification challenges. However, overcoming the mass transfer constraint and the catalyst's inherent site agglomeration in the heterogeneous system remains urgent. Herein, the abundant metal-anchored loading (≈6-8 g m -2 ) of alginate hydrogel membranes coupled with cross-flow mode as an efficient strategy for water purification applications is proposed. The organic flux of the confined hydrogel interfaces sharply enlarges with the reduction of the thickness of the boundary layer via the pressure field. The normalized property of the system displays a remarkable organic (sulfonamides) elimination rate of 4.87 × 10 4  mg min -1 mol -1 . Furthermore, due to the fast reaction time (<1 min), cross-flow mode only reaches a meager energy cost (≈2.21 Wh m -3 ) under the pressure drive field. It is anticipated that this finding provides insight into the novel design with ultrafast organic removal performance and low techno-economic cost (i.e., energy operation cost, material, and reagent cost) for the field of water purification under various PS-AOPs challenging scenarios., (© 2024 Wiley‐VCH GmbH.)

Exploiting emissive hydrophobic nanoclusters for hydrophilic applications remains a challenge because of photoluminescence (PL) quenching during phase transfer. In addition, the mechanism underlying PL quenching remains unclear. In this study, the PL-quenching mechanism was examined by analyzing the atomically precise structures and optical properties of a surface-engineered Ag 29 nanocluster with an all-around-carboxyl-functionalized surface. Specifically, phase-transfer-triggered PL quenching was justified as molecular decoupling, which directed an unfixed cluster surface and weakened the radiative transition. Furthermore, emission recovery of the quenched nanoclusters was accomplished by using a supramolecular recoupling approach through the glutathione-addition-induced aggregation of cluster molecules, wherein the restriction of intracluster motion and intercluster rotation strengthened the radiative transition of the clusters. The results of this work offer a new perspective on structure-emission correlations for atomically precise nanoclusters and hopefully provide insight into the fabrication of highly emissive cluster-based nanomaterials for downstream hydrophilic applications., (© 2024 Wiley-VCH GmbH.)

Self-assembly of subnanometer (sub-1 nm) scale polyhedral building blocks can yield some superstructures with novel and interesting morphology as well as potential functionalities. However, achieving the self-assembly of sub-1 nm polyhedral building blocks is still a great challenge. Herein, through encapsulating the titanium-substituted polyoxometalate (POM, K 7 PTi 2 W 10 O 40 ) with tetrabutylammonium cations (TBA + ), we first synthesized a sub-1 nm rhombic dodecahedral building block by further tailoring the spatial distribution of TBA + on the POM. Molecular dynamics (MD) simulations demonstrated the eight TBA + cations interacted with the POM cluster and formed the sub-1 nm rhombic dodecahedron. As a result of anisotropy, the sub-1 nm building blocks have self-assembled into rhombic dodecahedral POM (RD-POM) assemblies at the microscale. Benefiting from the regular structure, Br - ions, and abundant active sites, the obtained RD-POM assemblies exhibit excellent catalytic performance in the cycloaddition of CO 2 with epoxides without co-catalysts. This work provides a promising approach to tailor the symmetry and structure of sub-1 nm building blocks by tuning the spatial distribution of ligands, which may shed light on the fabrication of superstructures with novel properties by self-assembly., (© 2023 Wiley-VCH GmbH.)

Transition metal oxide (TMO) anode materials in lithium-ion batteries (LIBs) usually suffer from serious volume expansion leading to the pulverization of structures, further giving rise to lower specific capacity and worse cycling stability. Herein, by introducing polyoxometalate (POM) clusters into TMOs and precisely controlling the amount of POMs, the MnZnCuO x -phosphomolybdic acid hybrid sub-1 nm nanosheets (MZC-PMA HSNSs) anode is successfully fabricated, where the special electron rich structure of POMs is conducive to accelerating the migration of lithium ions on the anode to obtain higher specific capacity, and the non-covalent interactions between POMs and TMOs make the HSNSs possess excellent structural and chemical stability, thus exhibiting outstanding electrochemical performance in LIBs, achieving a high reversible capacity (1157 mAh g -1 at 100 mA g -1 ) and an admirable long-term cycling stability at low and high current densities., (© 2023 Wiley-VCH GmbH.)

Timely and remote biomarker detection is highly desired in personalized medicine and health protection but presents great challenges in the devices reported so far. Here, we present a cost-effective, flexible and self-powered sensing device for H 2 S biomarker analysis in various application scenarios based on the structure of galvanic cells. The sensing mechanism is attributed to the change in electrode potential resulting from the chemical adsorption of gas molecules on the electrode surfaces. Intrinsically stretchable organohydrogels are used as solid-state electrolytes to enable stable and long-term operation of devices under stretching deformation or in various environments. The resulting open-circuit sensing device exhibits high sensitivity, low detection limit, and excellent selectivity for H 2 S. Its application in the non-invasive halitosis diagnosis and identification of meat spoilage is demonstrated, emerging great commercial value in portable medical electronics and food security. A wireless sensory system has also been developed for remote H 2 S monitoring with the participation of Bluetooth and cloud technologies. This work breaks through the shortcomings in the traditional chemiresistive sensors, offering a direction and theoretical foundation for designing wearable sensors catering to other stimulus detection requirements., (© 2023. Springer Nature Limited.)

Membrane separation technology represented by graphene oxide (GO) membranes has been widely used in lithium extraction from salt lakes. It is extraordinary to study the extraction of Li + by GO membranes from the perspective of the confined mass transfer effect. This study establishes a GO channel model with the confined mass transfer effect to closely fit the actual mass transfer process. Meanwhile, this study investigates the dynamic fluid characteristics in the separation of Li + /Mg 2+ by GO membranes using molecular dynamics simulations. The results showed that the Li + /Mg 2+ separation ratio is maximum at 1.0 nm layer spacing and 10% oxidation degree of the GO membrane. Water molecules form a bilayer within the channel at the appropriate interlayer channel (1 nm) and oxidation level (10%), which accelerates the ion transport rate. Furthermore, the GO oxidation group has the weakest hydrogen bonding effect on water which promotes the passage of water. Finally, the maximum separation ratio is reached due to the fact that the binding force of Li + to water molecules in the channel is lower than that of Mg 2+ . The results of this study will provide theoretical consideration for the design of high-performance Li + /Mg 2+ separation membranes.

Sub-1 nm nanowires (SNWs) combine the properties of inorganic materials and polymers. They can be highly oriented through assembly, and can also be easily processed. Meanwhile, aggregation-induced emission luminogens (AIEgens) show high potential for optical applications, but they are usually hard to process. The combination of SNWs and AIEgens can enrich both of their applications. In this study, we report that the fluorescence emission intensity of the AIEgens-SNW dispersion is dramatically enhanced due to the flexibility of SNWs. Furthermore, we fabricate two kinds of functional films with circularly polarized luminescence (CPL) and linearly polarized luminescence (LPL) activities. The construction of CPL materials didn't require any chiral chemicals. The construction of LPL materials didn't require an additional stretching process. As a result, we endowed common achiral AIEgens with a high dissymmetry factor of 0.033 and a polarization ratio of 0.44, respectively., (© 2022 Wiley-VCH GmbH.)

Two-dimensional (2D) structures have been shown to possess interesting and potentially useful properties. Because of their isotropic structure, however, clusters tend to assemble into 3D architectures. Here we report the assembly of polyoxometalate clusters into layered structures that feature uniform hexagonal pores and in-plane electron delocalization properties. Because these structures are 2D and visually reminiscent of graphene, they are referred to as 'clusterphenes'. A series of multilayer and monolayer clusterphenes have been constructed with 13 types of polyoxometalate cluster. The resulting clusterphenes were shown to exhibit substantially improved stability and catalytic efficiency towards olefin epoxidation reactions, with a turnover frequency of 4.16 h -1 , which is 76.5 times that of the unassembled clusters. The catalytic activity of the clusterphenes derives from the electron delocalization between identical clusters within the 2D layer, which efficiently reduces the activation energy of the catalytic reaction., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

In nanoparticle self-assembly, the current lack of strategy to modulate orientational order creates challenges in isolating large-area plastic crystals. Here, we achieve two orientationally distinct supercrystals using one nanoparticle shape, including plastic crystals and uniform metacrystals. Our approach integrates multi-faceted Archimedean polyhedra with molecular-level surface polymeric interactions to tune nanoparticle orientational order during self-assembly. Experiments and simulations show that coiled surface polymer chains limit interparticle interactions, creating various geometrical configurations among Archimedean polyhedra to form plastic crystals. In contrast, brush-like polymer chains enable molecular interdigitation between neighboring particles, favoring consistent particle configurations and result in uniform metacrystals. Our strategy enhances supercrystal diversity for polyhedra comprising multiple nondegenerate facets., (© 2020 Wiley-VCH GmbH.)

When the size of nanomaterials reduces to the sub-1 nm scale, benefiting from size-induced mechanical flexibility and nearly 100% exposure of surface atoms, some new physical and chemical phenomena emerge, such as flexibility and polymer-like rheology. However, how to design and synthesize superflexible and high-performance hybrid sub-1 nm superstructures remains a great challenge. Herein, by incorporating four kinds of tungsten-based polyoxometallate (POM) clusters into the synthetic system of MoO 3 during the nucleation step, we successfully prepared four kinds of super-flexible hybrid sub-1 nm nanobelt superstructures (HSNSs). Molecular dynamics (MD) simulations demonstrated that POM clusters interacted with MoO 3 molecules and co-assembled into stable HSNSs, which could shrink, bend, curl and twist randomly in space and show super-flexible properties. These four kinds of MoO 3 -POM HSNSs not only performed high photothermal conversion but also showed excellent catalytic activity in the oxidation of thioethers at room temperature. This work paves the way for synthesis and broader applications of super-flexible cluster-inorganic-materials-based HSNSs.

Inorganic single crystals with anisotropic structures usually suffer from high brittleness and stiffness. Flexible polymers are used to replace inorganic crystals, but the hot-stretching-induced orientation process is tedious, and oriented molecular chains tend to revert to random coils during aging. To overcome these obstacles and using the similarities between sub-1 nm nanowires (NWs) and linear polymers, we successfully fabricated anisotropic, transparent, flexible, and stable (ATFS) NW films with great potential for optical applications through a wet-spinning method. The NW films show birefringence, and their birefractive index is higher than that of many polymers. They also showed polarized absorption of UV light and anisotropic scattering of visible light. The integrated films composed of NWs and quantum dots showed good fluorescence polarization. The tedious synthesis of quantum rods and fabrication of oriented polymer films can thus be avoided., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Substrate-molecule vibronic coupling enhancement, especially the efficient photoinduced charge transfer (PICT), is pivotal to the performance of nonmetal surface-enhanced Raman scattering (SERS) technology. Here, through developing novel two-dimensional (2D) amorphous TiO 2 nanosheets (a-TiO 2 NSs), we successfully obtained an ultrahigh enhancement factor of 1.86 × 10 6 . Utilizing the Kelvin probe force microscopy (KPFM) technology, we found that these 2D a-TiO 2 NSs possessed more positive surface potential than their 2D crystalline counterpart (c-TiO 2 NSs). First-principles density functional theory (DFT) was used to further reveal that the low coordination number of surface Ti atoms and the large amount of surface oxygen defects endowed the 2D a-TiO 2 with high electrostatic potential, which allowed significant charge transfer from the adsorbed molecule to the 2D a-TiO 2 and facilitated the formation of a stable surface charge-transfer (CT) complex. Significantly, comparing with the 2D c-TiO 2 , the smaller band gap and higher electronic density of states (DOS) of the 2D a-TiO 2 effectively enhanced the vibronic coupling of resonances in the substrate-molecule system. The strong vibronic coupling within the CT complex obviously enhanced the PICT resonance and lead to the remarkable SERS activity of a-TiO 2 NSs. To the best of our knowledge, this is the first report on the remarkable SERS activity of 2D amorphous semiconductor nanomaterials, which may bring the cutting edge of development of stable and highly sensitive nonmetal SERS technology.

Enhancement of the semiconductor-molecule interaction, in particular, promoting the interfacial charge transfer process (ICTP), is key to improving the sensitivity of semiconductor-based surface enhanced Raman scattering (SERS). Herein, by developing amorphous ZnO nanocages (a-ZnO NCs), we successfully obtained an ultrahigh enhancement factor of up to 6.62×10 5 . This remarkable SERS sensitivity can be attributed to high-efficiency ICTP within a-ZnO NC molecule system, which is caused by metastable electronic states of a-ZnO NCs. First-principles density functional theory (DFT) simulations further confirmed a stronger ICTP in a-ZnO NCs than in their crystalline counterparts. The efficient ICTP can even generate π bonding in Zn-S bonds peculiar to the mercapto molecule adsorbed a-ZnO NCs, which has been verified through the X-ray absorption near-edge structure (XANES) characterization. To the best of our knowledge, this is the first time such remarkable SERS activity has been observed within amorphous semiconductor nanomaterials, which could open a new frontier for developing highly sensitive and stable SERS technology., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The use of sunlight to drive organic reactions constitutes a green and sustainable strategy for organic synthesis. Herein, we discovered that the earth-abundant aluminum oxide (Al 2 O 3 ) though paradigmatically known to be an insulator could induce an immense increase in the selective photo-oxidation of different benzyl alcohols in the presence of a large variety of dyes and O 2 . This unique phenomenon is based on the surface complexation of benzyl alcohol (BnOH) with the Brønsted base sites on Al 2 O 3 , which reduces its oxidation potential and causes an upshift in its HOMO for electron abstraction by the dye. The surface complexation of O 2 with Al 2 O 3 also activates the adsorbed O 2 for receiving electrons from the photoexcited dyes. This discovery brings forth a new understanding on utilizing surface complexation mechanisms between the reactants and earth abundant materials to effectively achieve a wider range of photoredox reactions.