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The construction of a broad-spectrum photocatalytic system is of great significance for maximizing the utilization of solar energy. Herein, a surface oxygen vacancy triggering high-efficient broad-spectrum BiOCl

To explore whether sequential embryo transfer benefits patients with repeated implantation failure (RIF) undergoing frozen-thawed embryo transfer (FET) cycles.We included 311 patients with a history of RIF in this retrospective study. We did sequential transfers with a cleavage embryo on day 3 and a blastocyst on day 5 in 77 patients; blastocyst transfers with two blastocysts on day 5 in 80 patients; and cleavage embryo transfers with two cleavage embryos on day 3 in 154 patients. We compared clinical outcomes between the three groups.The clinical pregnancy rate was comparable between the blastocyst transfer group (48.8%), the sequential transfer group(48.1%) and the cleavage embryo transfer group (48.1%). There was no statistically significant difference found (p 0.05). The ongoing pregnancy and multipregnancy rates were also comparable between the three groups (p 0.05). The early miscarriage rate was significantly higher in the sequential transfer group (32.4%) compared with the blastocyst group (12.8%) and the cleavage embryo group (12.2%) (p 0.05). However, after adjusting for confounders, there was no significant difference in early miscarriage rates in the sequential transfer group compared with the blastocyst group (odds ratio [OR], 2.97; 95% confidence interval [CI], 0.85-9.24; p = 0.07) and the cleavage embryo group (OR, 3.03; 95% CI, 0.94-8.06; p = 0.08).Sequential embryo transfer failed to improve clinical outcomes for patients with RIF.

We report the proof-of-concept design of interfacial sites with a selectivity-governing and hydrogen evolution reaction-suppressing domain (Bi) and an electrokinetic-promoting domain (Cu2S) for efficient CO2 electroreduction to formate.

Catalysis in a confined space has attracted much attention due to the simultaneously designable nature of active sites and their microenvironment, leading to a broad spectrum of highly efficient chemical conversion schemes. Recent work has extended the scope of confined catalysis to electrochemical reactions. Mechanistic studies suggest that the confined environment in electrocatalysis can modulate mechanical, electronic, and geometric effects, stabilizing important charge-transfer intermediates and promoting reaction kinetics. In this minireview, we first discuss the fundamental concepts of confined catalysis by summarizing density functional theory (DFT) calculations and experimental investigations. We then present the rational design and applications of space-confined electrocatalysts with emphasis on the confined environment provided by carbon-based materials. We specifically focus on metal-based materials confined in carbon nanotubes (CNTs) and their applications in emerging electrochemical reactions including the oxygen reduction reaction (ORR), water-splitting reactions, carbon dioxide reduction reaction (CO2RR), and nitrogen reduction reaction (NRR). Finally, the existing challenges, opportunities, and future directions of electrocatalysis in confined spaces are highlighted.

The electrochemical CO

Nitrogen and phosphorus co-doped graphene quantum dot-modified Bi5O7I (NPG/Bi5O7I) nanorods were fabricated via a simple solvothermal method. The morphology, structure, and optical properties of the as-prepared samples were investigated by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), and diffused reflectance spectroscopy. The photocatalytic performance was estimated by degrading the broad-spectrum antibiotics tetracycline and enrofloxacin under visible light irradiation. The photodegradation activity of Bi5O7I improved after its surface was modified with NPGs, which was attributed to an increase in the photogenerated charge transport rate and a decrease in the electron-hole pair recombination efficiency. From the electron spin resonance spectra, XPS valence band data, and free radical trapping experiment results, the main active substances involved in the photocatalytic degradation process were determined to be photogenerated holes and superoxide radicals. A possible photocatalytic degradation mechanism for NPG/Bi5O7I nanorods was proposed.

Ultrathin BiOBr nanosheets have been prepared via an ionic liquid induced mechanochemical synthesis method at ambient temperature for the first time using 1-hexadecyl-3-methy-limidazolium bromine ([C16mim]Br). Transmission electron microscope and atomic force microscope images show that the ultrathin BiOBr nanosheets possessed an average diameter of approximately 200–300 nm with a thickness of 3–4 nm. For comparison, KBr was selected as Br source for the preparation of BiOBr nanosheets and the experimental results demonstrate that the ionic liquid and mechanical ball milling method had a significant impact on the fabrication of nanosheet structures. Compared with the as-prepared control samples, the ultrathin BiOBr nanosheet photocatalyst exhibited significantly increased photocatalytic performance for the removal of organic pollutants. A possible mechanism for this enhanced activity was proposed based on the shorter diffusion distance for charge transfer provided by the ultrathin nanosheet structure, which inhibits the recombination of photogenerated charge carriers. This work not only opens up a possible pathway for the large-scale industrial preparation of BiOX (X = Cl, Br, I) with superior photocatalytic activity, but also provides new insight into environmental restoration and energy conversion.

Ultrathin MoS2 nanosheet hybridized Bi5O7I (MoS2/Bi5O7I) nanorods were synthesized via a reactable ionic liquid assisted solvothermal process for the first time. The photocatalytic activity of MoS2/Bi5O7I nanorods was determined by photodegrading bisphenol A (BPA), tetracycline hydrochloride (TC) and ciprofloxacin (CIP) under visible light irradiation. Experimental results showed that MoS2/Bi5O7I owned the excellent photocatalytic properties and photostability. The efficient visible light driven photocatalytic performance was due to a larger specific surface area of MoS2, which increased the close interfacial contact between pollutants and photocatalysts. Meanwhile, the introduction of ultrathin MoS2 nanosheet was conducive to the separation and utilization of photoinduced charge carriers, thus further suppressed high recombination rate in pure Bi5O7I nanorods. Moreover, a possible charge transfer path in MoS2/Bi5O7I composite material was also put forward.

Direct ethanol fuel cells are one of the most promising electrochemical energy conversion devices for portable electronics and electric vehicles. Highly efficient and robust electrocatalysts for the ethanol oxidation reaction are therefore desired. In this paper, we report a facile approach for synthesizing monodisperse PdSn/SnOx core/shell nanoparticles as high-performance catalysts for electrochemical ethanol oxidation reaction (EOR). The mass current density of PdSn/SnOx reached 3.2 A mgPd−1 at 0.85 V vs. RHE in 1 M KOH solution, which is 3.2 times higher than that of the commercial Pd catalyst. More importantly, these PdSn/SnOx core/shell nanoparticles exhibit enhanced stability compared with the commercial Pd catalyst. Density functional theory calculations suggest that the strong d–p orbital coupling and sp-electron transfer in the PdSn alloy weaken the adsorption of carbonaceous species, e.g., the acetate-evolution intermediate *CH3CO and the poisoning species *CO, at Pd sites. Consequently, the destabilization of these species facilitates their coupling with *OH, leading to enhanced EOR activity and poison resistance. Meanwhile, we found that amorphous SnOx layers possess rich Sn–Sn ensembles with stronger adsorption of *OH, providing a shuttling path of hydroxide ions to surface sites.

Owing to the exorbitant CO2 activation energy and unsatisfactory photogenerated charge separation efficiency, CO2 photoconversion still faces enormous challenges. In this study, a directional electron transfer channel has been established by decorating N-doped carbon quantum dots (N-CQDs) on the surface of Bi4MoO9 nanoparticles to ensure that more active electrons can participate in the CO2 reduction. The conduction band of Bi4MoO9 nanoparticles is calculated to be −1.55 eV versus the normal hydrogen electrode (NHE), pH = 7, which is negative enough to attain the photocatalytic CO2 reduction potential of −0.53 eV versus NHE, pH = 7. CO2 adsorption curves and in situ Fourier transform infrared spectra reveal that N-CQDs facilitate surface CO2 adsorption and activation, as well as CO desorption. In addition, steady-state photoluminescence and photoelectrochemical tests prove that the charge separation efficiency can be greatly enhanced by constructing N-CQDs/Bi4MoO9 composites. In the presence of pure water, N-CQDs/Bi4MoO9-2 composite achieved a CO yield of 16.22 μmol g−1 after 5 h Xe light illumination, which was 3.24 times higher than that of pure Bi4MoO9 (4.98 μmol g−1). This study offers a distinctive approach to the optimization of Bi4MoO9 photocatalysts and their application in energy conversion.

Surface defects in semiconductors have a significant role to tune the photocatalytic reactions. However, the dominant studied defect type is oxygen vacancy, and metal cation vacancies are seldom ex...

Exploring efficient strategies to increase CO2 photoreduction performance is a key challenge in the energy conversion field. Herein, a cooperative role involving an ultrathin 2D structure and surface defects is employed to design defective Bi2MoO6 ultrathin nanosheets, to boost the CO2 photoreduction activity under water with no sacrificial agent, co-catalyst or extra photosensitizer. Bi2MoO6 ultrathin nanosheets with surface “Bi O″ vacancy pairs are grown via a template-directed strategy, as proved by STEM-ADF and positron annihilation spectroscopy. The engineered “Bi O″ vacancy pairs tune the local atomic structure, electronic structure of Bi2MoO6 and serve as charge separation centers to boost the electron-hole separation. Meanwhile, the defective ultrathin structure favors the CO2 adsorption, activation and CO desorption processes. With the merits of atomically-thin configuration and surface defects, the defective Bi2MoO6 ultrathin nanosheets display 2.55 times improved CO formation rate than their bulk counterpart under light irradiation.

Mesoporous FeVO4 nanorods were successfully synthesized by calcining the precursor FeVO4·1.1H2O nanorods, which were obtained via a simple hydrothermal method in the presence of a reactable metal-ion-containing ionic liquid, 1-octyl-3-methylimidazolium tetrachloride ferrate(III) ([Omim]FeCl4). The structure and morphology of the prepared samples were examined using various characterization techniques. During the synthetic process, [Omim]FeCl4 acted as the solvent, reactant, and capping agent simultaneously. Moreover, the porous FeVO4 nanorods as the heterogeneous photo-Fenton-like semiconductor catalyst for the degradation of tetracycline and rhodamine B under visible light irradiation exhibited excellent photocatalytic activity. This excellent photocatalytic activity of the porous FeVO4 nanorods can be attributed to the synergistic effect of their high electron-hole pair separation rate, suitable band gap structure, and large specific surface area. The possible photocatalytic degradation mechanism of FeVO4/H2O2 photocatalytic systems was also discussed in detail.

Metal-organic frameworks (MOFs), a new class of porous and crystalline materials, which have drawn increasing attention in diverse areas. The development of highly active MOFs-based photocatalysts have become a research hotspot owing to the tunable semiconducting properties and highly porous nanostructure. The unique roles of photocatalysis by MOFs can be conventionally optimized towards addressing the environment and energy issues. In this paper, NH2-MIL-125(Ti)/BiOCl composite was studied as a novel visible-light responsive photocatalyst for the removal of organic contaminants. The composite displays significantly enhanced photocatalytic activity for contaminant degradation as compared with BiOCl and NH2-MIL-125(Ti), and the optimal NH2-MIL-125(Ti) content is 10 wt%. The remarkable enhancement of the photocatalytic performance can be ascribed to the absorption of visible-light as well as the efficient charge separation and transfer on the interface contact between BiOCl and NH2-MIL-125(Ti). Superoxide radicals and holes were determined to be the main active species in the photocatalytic process via the reactive species trapping experiments and electron spin resonance, and the plausible photocatalytic mechanism is presented. This work aims to provide guidelines for developing more organic-inorganic hybrid materials for environmental remediation.

Novel Carbon quantum dots modified Bi5O7I (CQDs/Bi5O7I) nanorod composites were prepared via an ionic liquid 1-ethyl-3-methylimidazolium iodide ([Emim]I) assisted solvothermal method for the first time. Series of characterization methods were used to explore the structural composition, morphology and optical properties of as-prepared CQDs/Bi5O7I photocatalysts. Compared with pure Bi5O7I nanorod, CQDs/Bi5O7I composites exhibited the increased the specific surface area and visible light capture capability so as to expose more active sites and make full use of sunlight. Meanwhile, the tight contact between CQDs and Bi5O7I was beneficial for the rapid separation and migration of photogenerated electron-hole pairs to further suppress the high recombination rate in the pure Bi5O7I nanorods. More generated superoxide radicals (O2 −) was detected by electron spin resonance analysis. In addition, the possible mechanism for the enhanced photocatalytic performance of CQDs/Bi5O7I composites was put forward.

Novel N-doped carbon quantum dots (N-CQDs) modified Bi4O5I2 hollow nanotubes photocatalysts have been prepared for the first time. Bi4O5I2 nanomaterials with hollow nanotube structure were designed to shorten the charge carriers’ migration distance from bulk phase to surface while the N-CQDs was modified to accelerate the surface charge transfer. Multiple characterization methods have been applied to explore the phase structure, elemental composition, optical absorption properties and photocatalytic performance of as-prepared N-CQDs/Bi4O5I2 composites. The N-CQDs/Bi4O5I2-0.2 composite showed higher photocatalytic activity for the removal of bisphenol A than pure Bi4O5I2 hollow nanotube under UV light, visible light, light above 580 nm, which exhibited the broad spectrum photocatalytic activity. ESR analysis demonstrated the N-CQDs modification can tune the concentration of reactive oxygen species (•OH and •O2−). Combined with free radical trapping experiment results, hole, •OH and •O2− were demonstrated to be the main active species and synergistically promoted the enhancement of photocatalytic activity for N-CQDs/Bi4O5I2 composite.

Solar-driven reduction of CO2 , which converts inexhaustible solar energy into value-added fuels, has been recognized as a promising sustainable energy conversion technology. However, the overall conversion efficiency is significantly limited by the inefficient charge separation and sluggish interfacial reaction dynamics, which resulted from a lack of sufficient active sites. Herein, Bi12 O17 Cl2 superfine nanotubes with a bilayer thickness of the tube wall are designed to achieve structural distortion for the creation of surface oxygen defects, thus accelerating the carrier migration and facilitating CO2 activation. Without cocatalyst and sacrificing reagent, Bi12 O17 Cl2 nanotubes deliver high selectivity CO evolution rate of 48.6 μmol g-1 h-1 in water (16.8 times than of bulk Bi12 O17 Cl2 ), while maintaining stability even after 12 h of testing. This paves the way to design efficient photocatalysts with collaborative optimizing charge separation and CO2 activation towards CO2 photoreduction.

In this study, S, N codoped graphene quantum dots/(BiO)2CO3 hollow microspheres have been fabricated by a facile electrostatic self-assembly method. The nanosized S, N:GQDs, which can be obtained b...

Novel carbon quantum dots (CQDs)/BiOBr composite photocatalysts have been constructed through a facile hydrothermal synthesis in the presence of ionic liquid 1-hexadecyl-3-methylimidazolium bromide ([C16mim]Br). Series of characterizations have been performed to confirm the uniform distribution of CQDs in BiOBr nanosheets and the synergistic effect for photocatalytic degradation organic pollutants between CQDs and BiOBr. The results show that 3.1 wt% CQDs/BiOBr photocatalyst possesses the best photocatalytic activity for the degradation of colorless antibiotic tetracycline (TC), endocrine disrupter bisphenol A (BPA) and dye rhodamine B (RhB), under visible light irradiation, which exhibited the highest photocatalytic performance. The enhanced photocatalytic performance for CQDs/BiOBr composites could be attributed to the wider optical absorption range and fast separation of photogenerated charge carriers after the introduction of CQDs. The key roles of CQDs for the enhanced photocatalytic activity of BiOBr have been discussed. A possible mechanism of CQDs/BiOBr on the enhancement of visible light performance was proposed.

The efficient separation of photoexcited electron-hole pairs acts as a significant factor and challenge for the enhanced photocatalytic activity of the photocatalyst. To pursue higher photocatalytic activity, carbon quantum dots (CQDs) modified bismuth oxychloride (BiOCl)/bismuth oxybromide (BiOBr) nanosheet photocatalyst has first been synthesized via an in situ ionic liquid-induced strategy. The bridge function of the ionic liquid ensures the uniform dispersal of CQDs on the surface of the BiOCl/BiOBr material. After the introduction of CQDs, the CQDs/BiOCl/BiOBr composite photocatalyst displayed enhanced photocatalytic activity for the photodegradation of several different types of organic contaminants such as rhodamine B, tetracycline hydrochloride, ciprofloxacin, and bisphenol A under the irradiation of visible light, and the BiOCl/BiOBr material loading with 5 wt% CQDs showed the best photocatalytic performance. The characterization results revealed that the introduction of CQDs could simultaneously improve the visible light absorption properties and separation efficiency of photoexcited electron-hole pairs. The electron spin resonance and radical quenching experiments demonstrated that during the photocatalytic reactions, holes and superoxide radicals were the main active species involved in the degradation of the contaminants, and the possible photocatalytic mechanism is presented. Therefore, this work provides an efficient pathway for the improved activity of the photocatalyst.

Novel visible-light-driven PbBiO2I materials have been successfully synthesized through a one-pot ethylene glycol assisted solvothermal process in the presence of 1-hexyl-3-methylimidazolium iodide ([Hmim]I). The morphologies, compositions and properties of the PbBiO2I materials were investigated by XRD, XPS, SEM, TEM, DRS and nitrogen adsorption–desorption isotherms. The results of SEM and TEM indicated that the as-prepared PbBiO2I samples were microspheres with a diameter of about 1.5 μm assembled by nanosheets. The photocatalytic performance of the prepared PbBiO2I materials was determined by colorless endocrine disrupting chemical bisphenol A (BPA) and antibiotic ciprofloxacin (CIP). PbBiO2I materials have a very good visible light response with band gap of 1.98 eV, thus result in better photocatalytic degradation activity. Under the visible light irradiation for 3 h, about 72.5% of the BPA could be removed by PbBiO2I microspheres. The main active species during the photodegradation process were determined to be superoxide radicals and holes.