We proposed an in situ interfacial growth method induced by the Pickering emulsion strategy to produce metal organic framework (MOF)/graphite oxide (GO) composites of Cu3(BTC)2/GO, in which GO was demonstrated to be a promising stabilizer for producing the Pickering emulsion and provided a large interfacial area for the in situ growth of Cu3(BTC)2 nanoparticles. When Cu3(BTC)2/GO composites were used as adsorbents for CO2 capture from the simulated humid flue gas, they showed both significantly improved thermodynamic and dynamic properties. Because most of the H2O molecules were adsorbed on the highly exfoliated GO sheets in Cu3(BTC)2/GO-m, CO2 uptake reached 3.30 mmol/g after exposure to the simulated flue gas for 60 min and remained unchanged for up to 120 min. This highlighted its potential application for real CO2 capture. More importantly, the in situ interfacial growth of nanoparticles induced by Pickering emulsions would be a promising strategy for designing and fabricating nanocomposites.

Recently, MOF-derived metal oxides have been demonstrated as excellent semiconductor materials. Their derivatives can retain the high porosity and high specific surface area of the parent MOFs, effectively improving the adsorption capacity and mass transfer rate of reactive substances. Herein, UiO-67 was selected as the substrate due to its high hydrothermal stability and high specific surface area. Through the in situ growth of TiO2 nanoparticles, a series of double metal composite catalysts (ZrxTi/C) were produced after calcination at 400 °C. The X-ray diffraction (XRD) patterns showed that the UiO-67 crystal structure of collapsed after calcination, forming a Zr-O-C/TiO2 heterojunction. Energy-dispersive spectrometry (EDS) mapping images showed that Ti, Zr, and O were evenly distributed throughout the materials without obvious aggregation. Compared to conventional inorganic semiconductor materials, ZrxTi/C heterojunction catalysts provided much higher BET surface area (317 m 2 g 1) for the effective enrichment of contaminants on the catalyst surface. Tetracycline was selected as a representative antibiotic to study photodegradation performance under a 300 W Xenon lamp. Among the obtained catalysts, the Zr0.3Ti/C heterojunction catalyst exhibited the best photocatalytic efficiency, achieving 98% degradation within 30 min in a 10 mgL 1 tetracycline solution. Fluorescence spectra, electrochemical impedance spectroscopy, and transient photocurrent responses showed that the Zr0.3Ti/C heterojunction catalyst exhibited the fastest charge-hole separation rate and a maximum photocurrent density of 8.75 Acm 2 , which was 2.64 and 3.71 times those of UiO-67 and UiO-670.3/TiO2, respectively. The mechanism of tetracycline photodegradation was determined by UV-visible diffuse-reflectance absorption spectroscopy, Mott-Schottky plots, and electron spin resonance technology. A direct Z-scheme charge separation path was formed by the transfer and recombination of photoexcited e  in the conduction band (CB) of Zr-O-C with h + in the valence band (VB) of TiO2, which effectively reduced the combination rate of e  and h + in Zr-O-C and TiO2. The photodegradation rate constant of Zr0.3Ti/C was 16 and 3.7 times those of TiO2 and Zr-O-C, respectively, due to its large specific surface area and excellent tetracycline adsorption performance. Furthermore, the Zr-O-C/TiO2 heterostructure exhibiting suitable energy level matching and containing highly conductive carbon material improved the separation and migration of electron-hole pairs. Mechanistic studies revealed that the three types of radicals, superoxide radicals (O2 •), hydroxyl radicals (•OH), and a small amount of holes (h +) simultaneously promoted tetracycline photodegradation. After five recycling tests, Zr0.3Ti/C heterojunction catalyst maintained 91.2% removal efficiency for tetracycline, indicating good cycle stability. Combining the synergistic effects of adsorption and photodegradation, using bimetallic heterojunction composites with high specific surface area i...

Fluorescence-based detection is one of the most efficient and cost-effective methods for detecting hazardous, aqueous Hg 2+ . We designed a fluorescent porous organic polymer (TPA-POP-TSC), with a "fluorophore" backbone and a thiosemicarbazide "receptor" for Hg 2+ -targeted sensing. Nanometer-sized TPA-POP-TSC spheres (nanoPOP) were synthesized under mini-emulsion conditions and showed excellent solution processability and dispersity in aqueous solution. The nanoPOP sensor exhibits exceptional sensitivity (K sv = 1.01 × 10 6 M −1 ) and outstanding selectivity for Hg 2+ over other ions with rapid response and full recyclability. Furthermore, the nanoPOP material can be easily coated onto a paper substrate to afford naked eye-based Hg 2+detecting test strips that are convenient, inexpensive, fast, highly sensitive, and reusable. Our design takes advantage of the efficient and selective capture of Hg 2+ by thiosemicarbazides (binding energy = −29.84 kJ mol −1 ), which facilitates electron transfer from fluorophore to bound receptor, quenching the sensor's fluorescence.

A 2D sandwich-like TiO-rGO composite was fabricated by the Pickering emulsion approach to improve the photocatalytic efficiency. Through an in situ growth of antase-TiO nanoparticles on the interface of O/W type GO Pickering emulsion, TiO nanoparticles were closely and densely packed on the surface of well-exfoliated rGO sheets; meanwhile, many mesoporous voids acting as the adsorption chamber and microreactor were produced. Evaluated by methylene blue (MB) degradation, its photocatalytic activity was prominent compared with the common TiO-based photocatalyst, with the rate constants 5 and 3.1 times higher under visible light and xenon lamp, respectively. When we applied it in the photocatalytic degradation of tetracycline hydrochloride (TCH, such as 10 ppm) under the visible light without adding any oxidants, the total removal efficiency was as high as 94% after 40 min. The mechanism of this good photocatalytic efficiency was illustrated by the scavenger trapping tests, which showed that this unique structure of TiO-rGO composite induced by the Pickering emulsion can significantly enhance the light absorption ability, accelerate the separation rate of electron-hole pairs, increase the adsorption capacity of organic pollutants, and hence improve the photocatalytic efficiency.