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The CO2 electrochemical reduction reaction (CO2ERR) is heralded for carbon dioxide and renewable energy utilization. However, complexities in catalyst optimization and reactor structure research hinder its practical application. Herein, rather than traditional catalyst optimization, emphasis is placed on refining the reactor structure to enhance gas–liquid mixing. The goal is to raise the CO2 concentration in the reaction zone and extend its residence refining CO2ERR. Building on prior reactor designs, this work introduces the N‐reactor (the nozzle‐type reactor) with a ring electrode suited for gas–liquid mixing and reaction interplay. Through finite element simulations using the gas–liquid flow model, compared with the S‐reactors (the wide‐straight‐type reactor and the narrow‐straight‐type reactor), the N‐reactor's ring electrode shows a 12.99% CO2 concentration rise in the electrode zone and a 67.11% surge at the cathode exit. As a consequence, the total concentration of the product methanol is increased by 6.37%, with a maximum concentration increase of 26.96% and a concentration increase of 49.08% at the cathode outlet. These results validate the feasibility of optimizing the reaction from the perspective of gas–liquid mixing flow and provide novel methods and ideas for further optimization of CO2ERR, contributing to the practical application of the technology. [ABSTRACT FROM AUTHOR]

Pyrolysis-free metal–organic frameworks (MOFs) with optimized particle sizes were used as capacitive deionization (CDI) materials in oxygenated saline water. Upon decreasing the particle size of the MOFs, excellent cycling stability and higher CDI performance were achieved. This was possibly due to the improvement in charge transfer and electrolyte permeation, uncovering the significance of particle size control in improving CDI performance. [ABSTRACT FROM AUTHOR]

Electrocatalytic conversion of waste nitric oxide into ammonia is a promising approach to achieve sustainable nitrogen fixation. Herein, a CoNi co‐oxides catalyst is designed for NH3 electrosynthesis with the merits of facilitating NO adsorption and reducing the reaction energy barrier. By synergistic coupling with anodic NO oxidation, electrocatalytic disproportionation of NO is first realized to simultaneously synthesize value‐added double nitrogen products (NH3 and nitrate) with increased total energy efficiency. Furthermore, decoupled acid–base asymmetric electrolyte design is proposed in a united assembled electrolyzer, enabling a high NH3 production rate (26.27 mg h−1 cm−2) with unit faradaic efficiency and a remarkable nitrate production rate of 68.41 mg h−1 cm−2 at the anode. A low cell voltage of 3.58 V is obtained by optimizing ion agglomeration within the membrane to promote the charge‐ion exchange and electrode kinetics. Technoeconomic analysis demonstrates the economic feasibility of recycling waste NO by the electrocatalytic disproportionation strategy. [ABSTRACT FROM AUTHOR]

Carbon aerogel (CA) based materials have multiple advantages, including high porosity, tunable molecular structures, and environmental compatibility. Increasing interest, which has focused on CAs as electrocatalysts for sustainable applications including oxygen reduction reaction (ORR), oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and CO2 reduction reaction (CO2RR) has recently been raised. However, a systematic review covering the most recent progress to boost CA-based electrocatalysts for ORR/OER/HER/CO2RR is now absent. To eliminate the gap, this critical review provides a timely and comprehensive summarization of the applications, synthesis methods, and principles. Furthermore, prospects for emerging synthesis, screening, and construction methods are outlined. [ABSTRACT FROM AUTHOR]

An interconnected and hierarchically structured electrode composed of a Cu nanoparticle‐modified flower‐like reduced graphene oxide‐decorated copper foam (Cu NP/f‐RGO/CF) is crafted and exploited for photoelectrocatalytic (PEC) reduction of CO2 in a TiO2 nanotube photoanode‐driven PEC cell. Anode photovoltage compensation confers a more negative cathode potential for CO2 reduction, thus leading to a synergistic effect between photocatalysis (PC) and electrocatalysis (EC). CO2 reduction rate under PEC condition is 5.4× higher than that of the simple sum under PC and EC processes. The well‐defined flower structure of RGO in the CF scaffold effectively prevents its self‐agglomeration, which increases its adsorption towards CO2 with improved electron‐transfer kinetics due to the 3D interconnected structure with abundant electron transfer pathways. DFT calculations further reveal the absorption and activation of CO2 on Cu NP/f‐RGO capitalize on the CC bond with RGO and OCu bond with Cu NPs, thereby leading to a bended and stretched structure. The enhanced CO2 adsorptivity and activation on the hierarchical Cu NP/f‐RGO/CF electrode significantly improve CO2 reduction and facilitate the conversion of C1 products to high‐order products. This research highlights the great prospect of anode photovoltage compensation enables synergistic photoelectrocatalysis and 3D hierarchical electrode for CO2 drastic reduction into high‐order products. [ABSTRACT FROM AUTHOR]

Porous carbon-based catalysts facilitate CO 2 photoelectrochemical reduction reaction (CO2PRR) through the high charge transfer ability and CO 2 adsorption ability. However, the design of catalysts with high selectivity towards high-order solar fuels (such as ethanol and propanol) remains challenging. Herein, catalysts of carbonized Zn/Co Zeolitic Imidazolat Frameworks with various pyrolysis hours (xh-C-Zn/Co ZIFs) were synthesized and accessed for high selective CO2PRR for the first time. XRD and TEM analyses show that the C containing functional groups in pristine Zn/Co ZIF are carbonized and turned into amorphous porous carbon, while many Co and ZnO nanoparticles are formed during the pyrolysis process. Electrochemical characterizations of the catalysts prove that increasing pyrolysis time of Zn/Co ZIF from 1 h to 3 h, resulting in a decreased light current density from 3.3 mA/cm2 to 2.3 mA/cm2, which is much higher than that of Zn/Co ZIF (1.9 mA/cm2). Meanwhile, increasing pyrolysis time of Zn/Co ZIF from 1 h to 3 h results in decreased BET surface area and CO 2 adsorption ability. XPS spectra suggest a decreased content of metal-nitrogen bonds in C–Zn/Co ZIF, which leads to the formation of coordinatively unsaturated metal-nitrogen sites. Density functional theory (DFT) calculations reveal that the coordinatively unsaturated CoN 3 V sites in C–Zn/Co ZIF had the highest catalytic activity towards high-order organics. The total carbon atom conversion rate reaches 5459 nmol/h·cm2 when 1h-C-Zn/Co ZIF is employed as catalyst in the CO2PRR system and the selectivity towards high-order solar fuel reaches 84%. • Coordinatively unsaturated sites containing C–Zn/Co ZIF is used in a CO 2 PEC. • The 1h-C-Zn/Co ZIF has the highest selectivity (84%) to high-order solar fuel. • CoN 3 V site is proved to be the most selective site to high-order solar fuel. [ABSTRACT FROM AUTHOR]

• HC is used to prepare porous carbon for SCs for the first time. • A SSA of 3272 m2/g with a capacitance of 227 F/g is maximumly achieved. • HC/KOH treatment doubles the performance of SCs compared with sole KOH activation. • HC is a potential preparation method of porous carbon with high efficiency. Hydrodynamic cavitation (HC), which can effectively induce sonochemical effects, is widely considered a promising process intensification technology. In the present study, HC was successfully utilized to intensify the alkali activation of GPs for SCs, for the first time. Five BDCMs were synthesized following the method reported in the literature. For comparison, four more BDCMs with HC-treated, among which a sample was further doped with nitrogen during the HC treatment, were prepared. Then all the samples were compared from microscopical characteristics to electrochemical performance as SCs materials. The morphology study demonstrated that the HC treatment had created many defects and amorphous carbon structures on the GP-based BDCMs, with the highest SSA reaching 3272 m2/g (1:6-HCGP), which 32 folded that of the Raw carbon sample's. The HC treatment also intensified the N-doping process. XRD and XPS results manifested that the N content had been increased and consequently changed the electronic structure of the carbon atoms, leading to the increase of specific capacitance (1:6-HCGP+N-based SC, 227 F/g at 10 A/g). The cycle performance proved that the GP-based BDCMs have long-term stability, indicating that the HC-treated BDCMs were good choices for energy storage technologies. Compared with the ultrasound-assisted method, which may have a high energy density, the HC-assisted method enables high production and energy efficiency. This work is a first time attempt towards the industrial application of HC method in energy-related materials synthesis and encourages more in-depth studies in the future. [ABSTRACT FROM AUTHOR]

A nanostructured Pt/graphene aerogel directly deposited in Cu foam (Pt/GA/CF) was used as a 3D binder-free cathode to convert CO 2 into liquid chemicals in a TiO 2 photoanode-driven photoelectrochemical cell. The surface morphology, microstructure, mineralogical and elemental compositions, and electrochemical performance of the Pt/GA/CF electrode were characterized via SEM/EDX, TEM, X-ray diffraction, X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy (EIS), and chronocoulometry (CC). EIS analysis revealed that Pt/GA/CF with reduced impedance possessed a better electron transfer capacity than the electrode that combines Pt-modified reduced graphene oxide with CF through polymer binders (Pt/RGO/CF). SEM and CC analyses confirmed that the uniform dispersion of 3D nanoporous Pt/GA in CF scaffold effectively prevented its self-agglomeration and increased the electrochemical adsorption surface area of Pt/GA/CF to 15 times higher than that of Pt/RGO/CF. The efficient charge transportation and high reactant adsorptivity of the Pt/GA/CF electrode significantly improved CO 2 reduction and facilitated the conversion of C1 products to high-order products. Formic acid, acetic acid, propionic acid, methanol, and ethanol were detected as the liquid products of CO 2 reduction. The carbon atom conversion rate of CO 2 reduction on Pt/GA/CF markedly increased to 5040 nmol/(h cm 2 ). [ABSTRACT FROM AUTHOR]

The low salt adsorption capacities (SACs) of benchmark carbon materials (usually below 20 mg g -1 ) are one of the most challenging issues limiting further commercial development of capacitive deionization (CDI), an energetically favorable method for sustainable water desalination. Sodium superionic conductor (NASICON)-structured NaTi 2 (PO 4 ) 3 (NTP) materials, especially used in combination with carbon to prepare NTP/C materials, provide emerging options for higher CDI performance but face the problems of poor cycling stability and dissolution of active materials. In this study, we report the development of the yolk-shell nanoarchitecture of NASICON-structured NTP/C materials (denoted as ys -NTP@C) using a metal-organic framework@covalent organic polymer (MOF@COP) as a sacrificial template and space-confined nanoreactor. As expected, ys -NTP@C exhibits good CDI performance, including exemplary SACs with a maximum SAC of 124.72 mg g -1 at 1.8 V in the constant-voltage mode and 202.76 mg g -1 at 100 mA g -1 in the constant-current mode, and good cycling stability without obvious performance degradation or energy consumption increase over 100 cycles. Furthermore, X-ray diffraction used to study CDI cycling clearly exhibits the good structural stability of ys -NTP@C during repeated ion intercalation/deintercalation processes, and the finite element simulation shows why yolk-shell nanostructures exhibit better performance than other materials. This study provides a new synthetic paradigm for preparing yolk-shell structured materials from MOF@COP and highlights the potential use of yolk-shell nanoarchitectures for electrochemical desalination.

Using scientific technologies to detect toxins in food is significant to prevent food safety problems and protect people's health. Recently, the rise of sensors has made rapid, efficient, and safe detection of food toxins possible. One of the key factors impacting the sensor's performance is the nanomaterials employed. Metal-organic frameworks (MOFs), with high specific surface area, tunable composition, porous structure, and flexible properties, have aroused the interest of researchers. The applications of MOFs in detecting food toxins have seen remarkable success in the past few years. In this critical mini-review, the impact of various synthesis methods on MOFs' properties is first presented. Then, the applications and mechanisms of MOFs-based sensors in detecting various toxins are summarized and analyzed. Finally, future perspectives, potential opportunities, and challenges in this field are discussed., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Xuan, Wang, Manickam, Boczkaj, Yoon and Sun.)

Pesticide residues are of great significant issue that exerted adverse effects on humans. There is a need for effective and non-toxic decontamination of pesticide residues during food processing. In this minireview, the recent advances in the degradation of pesticide residues by photolysis have been firstly described during food processing. The mechanisms of pesticide residues destruction by photolysis were discussed accordingly. Finally, applications of photolysis in the degradation of pesticide residues from beverages, fresh produce, and food rinse waste were also summarized., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Xiao, Xuan, Boczkaj, Yoon and Sun.)

Hydrodynamic cavitation (HC), as a novel non-thermal processing technology, has recently shown unique effects on the properties of various liquid foods. The extreme conditions of pressure at ~500 bar, local hotspots with ~5,000 K, and oxidation created by HC can help obtain characteristic products with high quality and special taste. Moreover, compared with other emerging non-thermal approaches, the feature of the HC phenomenon and its generation mechanism helps determine that HC is more suitable for industrial-scale processing. This mini-review summarizes the current knowledge of the recent advances in HC-based liquid food processing. The principle of HC is briefly introduced. The effectiveness of HC on the various physical (e.g., particle size, viscosity, temperature, and stability), chemical (nutrition loss), and biological characteristics (microorganism inactivation) of various liquid foods are evaluated. Finally, several recommendations for future research on the HC technique are provided., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Sun, You, Wu, Tao, Yoon, Zhang and Xuan.)

The rise of CO 2 in the atmosphere, which results in severe climate change and temperature increase, is known as the major reason for the greenhouse effect. Reducing CO 2 to value-added products is an attractive solution to this severe problem, along with addressing the energy crisis, to which the catalysts being employed are of vital importance. Due to their high porosity and tunable compositions, metal-organic frameworks (MOFs) show great potential in energy conversion systems. By thermal or chemical treatment methods, the MOFs are easily turned into MOF-derived carbon nanomaterials. The much higher level of conductivity enables MOF-derived carbon nanomaterials to be employed in CO 2 conversion processes. The present review, discusses the state of the art of MOF-derived carbon nanomaterials in CO 2 electrochemical, photocatalytic, and thermal reduction applications. The corresponding reaction mechanisms and influence of various factors on catalyst performance are elaborated. Finally, the deficiencies and recommendations are provided for future progress., (Copyright © 2020 Xuan, Chen, Zhao, Yoon, Boczkaj and Sun.)

To promote the faradaic efficiency of the electrocatalytic CO2 reduction reaction (CO2RR) with low-cost catalysts, single Ni atoms with higher positive charges induced by hydroxyls were proposed to form an atomically dispersed Ni-N4 structure in a cheap honeycomb-like carbon matrix for electrocatalytic CO2 reduction. Extended X-ray absorption fine structure spectroscopy, aberration-corrected High-angle annular dark-field scanning transmission electron microscopy and X-ray photoelectron spectroscopy measurements confirmed that the active-center structure consists of single Ni atoms and the adjacent hydroxyl via hydrothermal treatment (H-Ni/NC). Density functional theory calculations indicated that the isolated Ni atoms with higher positive charges induced by the hydroxyl decreased the free energy of the rate-limiting step to 1.05 eV for the CO2RR. The faradaic efficiency (FE) of CO2 reduction into CO was ≥88.0% over the H-Ni/NC catalyst in the potential range of -0.5 to -0.9 V (vs. RHE). The peak CO FE reached 97% at -0.7 V due to the synergistic effect between the unsaturated Ni-N4 active sites and the hydroxyl species.

To efficiently and selectively produce liquid hydrocarbon fuels, e.g., methanol, by CO 2 photoelectrochemical reduction, CdS nanoparticles (NPs) anchored on the nitrogen-doped carbon particles (NCP) with core-shell dodecahedral porous structure were used as cathode catalysts. Electron paramagnetic resonance (EPR) spectra indicated that CdS/NCP treated at 500 °C had the maximum S-vacancies. The heterojunction generated between CdS with abundant S-vacancies and NCP with a high content of pyridinic N acted as synergistic catalyst for CO 2 reduction. CdS/NCP-500 catalyst exhibited a selectivity of 77.3% towards methanol with a total carbon atom conversion rate of 3052 nmol·h -1 ·cm -2 . Density functional theory (DFT) calculations revealed that the S-vacancies decreased the energy barrier for CO 2 conversion into methanol product. NCP, exhibiting a high adsorption capacity for CO 2 , allowed the conversion of COOH* into CO* (ΔE = -3.6 eV), which was then transferred to the CdS surface displaying abundant S-vacancies for the reduction into the methanol product., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Carbon supported nano-metal catalysts are expected to improve CO 2 reduction selectivity and efficiency due to the addition of more active sites and enhancement of electron transport ability. In this study, HKUST-1 was pyrolyzed and decorated with Pt to prepare Pt-Cu/C catalysts. The catalytic effect of the catalysts with different Pt contents in the CO 2 photoeletrochemical reduction reaction (CO 2 PRR) were compared. The total carbon atom conversion rate in CO 2 PRR experiments using Pt-Cu/C catalysts first increased to a peak when using 1.6 wt% Pt-Cu/C catalyst and then decreased with the increase of Pt content. The 1.6 wt% Pt-Cu/C catalyst showed good hydrogen evolution reaction (HER) inhibiting ability compared with other Pt-Cu/C catalysts. Density functional theory (DFT) calculations were conducted to give an insight into the CO 2 PRR mechanism on some possible active sites in Pt-Cu/C catalysts. The result demonstrated that HER was more likely to be inhibited on the Cu/Pt active surface and at the same time CO 2 PRR was promoted., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

To increase the reaction productivity and selectivity of the CO 2 photoelectrochemical reduction reaction, a Cu (benzene 1,3,5-tricarboxylic acid [BTC])-reduced graphite oxide (rGO) catalyst was prepared by using a facile hydrothermal method and used in a CO 2 photoelectrochemical cell (PEC) as a cathode catalyst. Characterization of the catalyst proved that successfully bonding of rGO to Cu(BTC) not only facilitated faster transfer of electrons on the surface of the catalyst but also created more active sites. CO 2 photoelectrochemical reduction experimental results showed that the total carbon atom conversion rate was up to 3256 nmol h -1 cm -2 which was much higher than when pure Cu(BTC) was used as a cathode catalyst. The liquid product's selectivity to alcohols was up to 95% when -2 V voltage was applied to the system with Cu(BTC)-rGO used as the cathode catalyst., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)