This paper reports the results from a second characterisation of the 91500 zircon, including data from electron probe microanalysis, laser ablation inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS), secondary ion mass spectrometry (SIMS) and laser fluorination analyses. The focus of this initiative was to establish the suitability of this large single zircon crystal for calibrating in situ analyses of the rare earth elements and oxygen isotopes, as well as to provide working values for key geochemical systems. In addition to extensive testing of the chemical and structural homogeneity of this sample, the occurrence of banding in 91500 in both backscattered electron and cathodoluminescence images is described in detail. Blind intercomparison data reported by both LA‐ICP‐MS and SIMS laboratories indicate that only small systematic differences exist between the data sets provided by these two techniques. Furthermore, the use of NIST SRM 610 glass as the calibrant for SIMS analyses was found to introduce little or no systematic error into the results for zircon. Based on both laser fluorination and SIMS data, zircon 91500 seems to be very well suited for calibrating in situ oxygen isotopic analyses.

H 2 O 2 production by electroreduction of O 2 is an attractive alternative to the current anthraquinone process, which is highly desirable for chemical industries and environmental remediation. However,i tr emains ag reat challenge to develop cost-effective electrocatalysts for H 2 O 2 synthesis.Here, hierarchically porous carbon (HPC) was proposed for the electrosynthesis of H 2 O 2 from O 2 reduction. It exhibited high activity for O 2 reduction and good H 2 O 2 selectivity (95.0-70.2 %, most of them > 90.0 %a tp H1-4 and > 80.0 %a t pH 7). High-yield H 2 O 2 generation has been achieved on HPC with H 2 O 2 concentrations of 222.6-62.0 mmol L À1 (2.5 h) and corresponding H 2 O 2 production rates of 395.7-110.2 mmol h À1 g À1 at pH 1-7 and À0.5 V. Moreover,H PC was energy-efficient for H 2 O 2 production with current efficiency of 81.8-70.8 %. The exceptional performance of HPC for electrosynthesis of H 2 O 2 could be attributed to its high content of sp 3 -C and defects,l arge surface area and fast mass transfer.

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Pharmaceutical antibiotics are not easily removed from water by conventional water-treatment technologies and have been recognized as new emerging pollutants. Herein, we report the synthesis of clickable azido periodic mesoporous organosilicas (PMOs) and their use as adsorbents for the adsorption of antibiotics. Ethane-bridged PMOs, functionalized with azido groups at different densities, were synthesized by the co-condensation of 1,2-bis(trimethoxysilyl)ethane (BTME) and 3-azidopropyltrimethoxysilane (AzPTMS), in the presence of nonionic-surfactant triblock-copolymer P123, in an acidic medium. Four different alkynes were conjugated to azide-terminated PMOs by means of an efficient click reaction. The clicked PMOs showed improved adsorption capacity (241 μg g(-1)) for antibiotics (ciprofloxacin hydrochloride) compared with azido-functionalized PMOs because of the enhanced π-π stacking interactions. These results indicate that click reactions can introduce multifunctional groups onto PMOs, thus demonstrating the great potential of PMOs for environmental applications.

films were developed on titanium substrates by applying dip-coating technique formed by the sol-gel method. Scanning electron microscopy (SEM) evaluated the surface characteristics of the films. Results on their structure and crystallinity were obtained by means of X-ray diffraction. The samples were also characterized by X-ray energy dispersive spectrometer (EDS) and ultraviolet-visible diffuse reflectance spectroscopy. The photocatalytic activity of these films towards photodegradation of pentachlorophenol pollutant was examined and their efficiency was compared to those of the different TiO 2 films. It has been shown that the film photocatalysts can efficiently decompose the pollutant. The photoelectrocatalytic degradation of PCP showed important variation that decreases in the order: ZnO/TiO 2 > TiO 2 > Fe 2 O 3 /ZnO/TiO 2 > Fe 2 O 3 /TiO 2 . The results showed that Zn 2þ doped could improve PEC activity of titania film electrode while Fe 3þ doped can not improve that of titania film electrode. R E S E A R C H P A P E RT h i s j o u r n a l i s Q T h e O w n e r S o c i e t i e s 2 0 0 4 P h y s . C h e m . C h e m . P h y s . , 2 0 0 4 , 6 , 6 5 9 -6 6 4 659