Search

We report the implementation of the ligand‐to‐metal charge transfer (LMCT) in organic semiconductors for improved full visible‐light photocatalysis and understanding of the effects of Pd−N weak coordination of a single‐atomic Pd(II) embedded 2D g‐C3N4 (Pd1/UTCN) homogeneous catalyst analogues on the formation of open metal sites and LMCT induced full‐visible‐light photocatalytic performance. LMCT between Pd(II) and g‐C3N4 allows for wide‐range visible light harvesting and promoting the transport of photogenerated charge of carbon nitride from excitation site to active site. Compared to the porphyrin palladium complex with strong Pd−N coordination, the reversible coordination dissociation of Pd−N of Pd1/UTCN allows for the formation of open active sites photocatalysis, which enables the efficient adsorption, activation, and conversion of substrates. The adsorption of the substrate can promote LMCT between Pd(II) and heptanazine ligands. As a result, Pd1/UTCN exhibited LMCT‐induced efficient full‐visible‐light photocatalytic activity of Suzuki reaction with high selectivity without additional phosphorus ligands. [ABSTRACT FROM AUTHOR]

Photocatalytic H 2 O 2 production has gained significant attention as an environmentally friendly approach. The key is to explore efficient photocatalysts with sufficient active sites and excellent electron transfer capacity. Herein, we propose a novel approach by incorporating carbon dots (CDs) on ethylenediamine capped Zn 0.5 Cd 0.5 S, which was bridged with an interfacial amide bond. Smooth transfer of photoinduced electrons from Zn 0.5 Cd 0.5 S to carbon dots via a high-speed electron channel is afforded by interfacial amide bond. A remarkable H 2 O 2 yield with a rate of 252 μmol/h and an apparent quantum yield (AQY) of 31 % at 400 nm is achieved. Photoelectrochemical analysis and density function theory (DFT) calculation reveal CDs with abundant oxygenous functional groups as active sites, boosting activity and selectivity. This interfacial engineering strategy with the acceleration of electrons transfer and enhanced 2e- selectivity can be applied to advanced photocatalytic systems for the achievement of valuable organics, environmental purification and new energy carriers. [Display omitted] • Carbon dots bridged Zn 0.5 Cd 0.5 S with interfacial amide bond was fabricated. • Amide bond enables smooth electron transfer to O 2 reduction center of carbon dots. • A 34-fold enhancement of H 2 O 2 production was achieved. [ABSTRACT FROM AUTHOR]

We demonstrate a new case of materials–gene engineering to precisely design photocatalysts with the prescribed properties. Based on theoretical calculations, a phase‐doping strategy was proposed to regulate the pathways of CO2 conversion over Au nanoparticles (NPs) loaded TiO2 photocatalysts. As a result, the thermodynamic bottleneck of CO2‐to‐CO conversion is successfully unlocked by the incorporation of stable twinning crystal planes into face‐centered cubic (fcc) phase Au NPs. Compared to bare pristine TiO2, the activity results showed that the loading of regular fcc‐Au NPs raised the CO production by 18‐fold but suppressed the selectivity from 84 % to 75 %, whereas Au NPs with twinning (110) and (100) facets boosted the activity by nearly 40‐fold and established near unity CO selectivity. This enhancement is shown to originate from a beneficial shift in the surface reactive site energetics arising at the twinned stacking fault, whereby both the CO reaction energy and desorption energy were significantly reduced. [ABSTRACT FROM AUTHOR]

We demonstrate a new case of materials–gene engineering to precisely design photocatalysts with the prescribed properties. Based on theoretical calculations, a phase‐doping strategy was proposed to regulate the pathways of CO2 conversion over Au nanoparticles (NPs) loaded TiO2 photocatalysts. As a result, the thermodynamic bottleneck of CO2‐to‐CO conversion is successfully unlocked by the incorporation of stable twinning crystal planes into face‐centered cubic (fcc) phase Au NPs. Compared to bare pristine TiO2, the activity results showed that the loading of regular fcc‐Au NPs raised the CO production by 18‐fold but suppressed the selectivity from 84 % to 75 %, whereas Au NPs with twinning (110) and (100) facets boosted the activity by nearly 40‐fold and established near unity CO selectivity. This enhancement is shown to originate from a beneficial shift in the surface reactive site energetics arising at the twinned stacking fault, whereby both the CO reaction energy and desorption energy were significantly reduced. [ABSTRACT FROM AUTHOR]

Abstract The work proposed a distinct arrangement to construct the amperometric-type NO 2 sensor using pyrochlore-phase Pr 2 Zr 2 O 7 as oxygen-defect conductor. An effective co-doping strategy at A and B sites was explored to prepare the defective Pr 2-x M x Zr 1.95 In 0.05 O 7+δ (PMZI, M = Ca, Sr, Ba) oxygen conductors. DFT results show that the band structure of solid electrolyte are dependent of the doping elements at A and B sites. A-site doping theoretically causes 48f and 8b oxygen defects, yet only 48f oxygen defect for B-site doping. Oxygen defect energy shows that Ca2+ doping at A site can be inclined to 8b oxygen defects, as opposed to Sr2+ and Ba2+ incorporation that can cause migratable 48f oxygen defects. DFT simulation indicates that the thermally excited electrons for the Ca2+ doping are uneasier to enter the conduction band through two deeper impurity levels, compared to Sr2+ and Ba2+ doping, as the dark current is lower for the PCZI sensors. The oxygen-defect induces both the electron transport and enhanced NO 2 sensing performances. The result of amperometric response obviously exhibits that the Δ I value of the optimized PCZI (0.02) sensor with high sensitivity (224 nA/ppm) is 15.11 and 12.26 times as high as the pure Pr 2 Zr 2 O 7 and commercial YSZ sensors, respectively, exhibiting the potential industrial application prospect. Highlights • Elaborating oxygen-defect sites caused by doping through theoretical calculation. • Alkaline earth metal ion serves as a dopant in view of its dual function. • Oxygen-defect induces the electron transport and enhanced NO 2 sensing performances. • Constructing the relationship between the dark current and band structure by DFT. [ABSTRACT FROM AUTHOR]

Oxygen defects in Hafnium Oxide (HfO2)-based ferroelectric thin films not only are related to the cause of ferroelectricity but also affect the ferroelectric properties of the thin films. This paper, therefore, focuses on the fabrication of Zr:HfO2 thin films by RF (Radio Frequency) magnetron sputtering with Zr-doped HfO2 as the target and examines how oxygen flow impacts the oxygen vacancies and electrical properties thereof. Additionally, TiN thin-film electrodes were prepared by direct current (DC) magnetron reactive sputtering using nitrogen as the reaction gas, the influences of the substrate temperature on the film deposition rate and crystal phase structure were investigated, and the resultant thin-film electrodes with the lowest resistivity were obtained. Furthermore, the ferroelectric hysteresis loop and leakage current density of metal–insulator–metal (MIM) ferroelectric capacitors formed by annealing the 30 nm thick deposited Zr:HfO2 sandwiched between the top and bottom TiN electrodes were measured. The results demonstrate that varying oxygen flow has a considerable effect on oxygen vacancies and the Zr doping concentration of deposited Zr:HfO2 ferroelectric thin films. When the oxygen flow is set to 40 sccm (standard cubic centimeters per minute) and an external electric field strength of 2 mV/cm is applied, the remnant polarization reaches 18 μC/cm2, with a decrease in the leakage current density of 105–6 orders of magnitude. [ABSTRACT FROM AUTHOR]

We demonstrate a new case of materials–gene engineering to precisely design photocatalysts with the prescribed properties. Based on theoretical calculations, a phase‐doping strategy was proposed to regulate the pathways of CO2 conversion over Au nanoparticles (NPs) loaded TiO2 photocatalysts. As a result, the thermodynamic bottleneck of CO2‐to‐CO conversion is successfully unlocked by the incorporation of stable twinning crystal planes into face‐centered cubic (fcc) phase Au NPs. Compared to bare pristine TiO2, the activity results showed that the loading of regular fcc‐Au NPs raised the CO production by 18‐fold but suppressed the selectivity from 84 % to 75 %, whereas Au NPs with twinning (110) and (100) facets boosted the activity by nearly 40‐fold and established near unity CO selectivity. This enhancement is shown to originate from a beneficial shift in the surface reactive site energetics arising at the twinned stacking fault, whereby both the CO reaction energy and desorption energy were significantly reduced. [ABSTRACT FROM AUTHOR]

We develop a new PdCu/UTCN hybrid by loading low-crystalline PdCu NPs on large-area ultrathin 2D carbon nitride (UTCN) nanosheets that exfoliated from bulk g-C 3 N 4 using a twice thermal exfoliation and repolymerization method for photocatalytic Suzuki C-C cross coupling reaction. Due to the advantages of 2D structure of the UTCN and the changes in electronic structure and surface structure of low-crystalline PdCu NPs, PdCu/UTCN shows promoted photocatalytic activity with high selectivity for Suzuki coupling reaction. The TOF value for coupling of iodobenzene with phenylboronic acid is 418.2 h−1, which is 8 and 6.2 times higher than that of previously reported Pd-g-C 3 N 4 and Pd based alloy photocatalysts under the same reaction, respectively. Morevoer, this photocatalyst shows a good functional group tolerance as well as good to excellent yield and selectivity for various substrates. This study reports for the first time the PdCu alloy supported UTCN photocatalytic material for enhanced Suzuki reaction. A new PdCu/UTCN hybrid by loading low-crystalline PdCu NPs on large-area ultrathin 2D carbon nitride (UTCN) nanosheets that exfoliated from bulk g-C 3 N 4 using a twice thermal exfoliation and repolymerization method for photocatalytic Suzuki C-C cross coupling reaction. [Display omitted] • Large-area ultrathin 2D carbon nitride nanosheets (UTCN) is successfully prepared. • PdCu/UTCN hybrid is constructed by loading low-crystalline PdCu NPs on UTCN. • PdCu/UTCN shows excellent photocatalytic activity for Suzuki coupling reaction. • UTCN has a large specific surface area and a higher charge separation efficiency. • Low-crystalline PdCu promotes charge separation, light harvesting, and reaction. [ABSTRACT FROM AUTHOR]

Sunlight-driven valorization of CO 2 into fuels is a promising solution to renewable energy storage, but the design of an integrated and efficient solar-to-chemical conversion system remains challenging. Herein, an all-solar-driven artificial photosynthetic system (APS) by tailoring photovoltaic-photoelectrochemical cell which can efficiently produce formic acid fuel from CO 2 and H 2 O with bias-free illumination is demonstrated. Guided by density functional theory (DFT) calculations, a BiOI–Bi (BOI–Bi) cathode catalyst is synthesized, which is highly selective for CO 2 to HCOOH conversion, and coupled with a single crystalline argon-treated TiO 2 (TiO 2 -Ar) photoanode, whose valence band edge is beneficial for the oxidation of H 2 O to O 2. The APS exhibits high product selectivity, robust activity and good durability. A solar-to-HCOOH selectivity of 96.5% is obtained with a HCOOH yield of 108.2 mmol g−1 h−1 under bias-free illumination of AM1.5G. The device can operate stably for at least 12 h. In particular, an apparent photon quantum efficiency of 7.5% and a solar-to-chemical conversion efficiency (η SCC) of 8.3% are recorded, rivaling all the incumbent precious-metal-free all-solar-driven components for CO 2 -to-HCOOH conversion. This study highlights the potential of BOI-Bi for CO 2 to HCOOH conversion with high selectivity and its integration into APS system to realize carbon-negative solar-to-chemical conversion with industrial relevance. • The pathways of selectively converting H C O 3 – /CO 2 -to-HCOOH is simulated. • The gain effect of VBM for potential distribution in PEC system is clarified. • The cell voltage of optimized APS meets the highest selectivity for HCOOH. • The APS exhibits a highest η S C C of 8.3% in all the precious-metal-free devices. [ABSTRACT FROM AUTHOR]

D‐π‐A type 4‐((9‐phenylcarbazol‐3‐yl)ethynyl)‐N‐dodecyl‐1,8‐naphthalimide (CZNI) with a large dipole moment of 8.49 D and A‐π‐A type bis[(4,4′‐1,8‐naphthalimide)‐N‐dodecyl]ethyne (NINI) with a negligible dipole moment of 0.28 D, were smartly designed and synthesized to demonstrate the evidence of a molecular dipole as the dominant mechanism for controlling charge separation of organic semiconductors. In aqueous solution, these two novel naphthalimides can self‐assemble to form nanoribbons (NRs) that present significantly different traces of exciton dissociation dynamics. Upon photoexcitation of NINI‐NRs, no charge‐separated excitons (CSEs) are formed due to the large exciton binding energy, accordingly there is no hydrogen evolution. On the contrary, in the photoexcited CZNI‐NRs, the initial bound Frenkel excitons are dissociated to long‐lived CSEs after undergoing ultrafast charge transfer within ca. 1.25 ps and charge separation within less than 5.0 ps. Finally, these free electrons were injected into Pt co‐catalysts for reducing protons to H2 at a rate of ca. 417 μmol h−1 g−1, correspondingly an apparent quantum efficiency of ca. 1.3 % can be achieved at 400 nm. [ABSTRACT FROM AUTHOR]

D‐π‐A type 4‐((9‐phenylcarbazol‐3‐yl)ethynyl)‐N‐dodecyl‐1,8‐naphthalimide (CZNI) with a large dipole moment of 8.49 D and A‐π‐A type bis[(4,4′‐1,8‐naphthalimide)‐N‐dodecyl]ethyne (NINI) with a negligible dipole moment of 0.28 D, were smartly designed and synthesized to demonstrate the evidence of a molecular dipole as the dominant mechanism for controlling charge separation of organic semiconductors. In aqueous solution, these two novel naphthalimides can self‐assemble to form nanoribbons (NRs) that present significantly different traces of exciton dissociation dynamics. Upon photoexcitation of NINI‐NRs, no charge‐separated excitons (CSEs) are formed due to the large exciton binding energy, accordingly there is no hydrogen evolution. On the contrary, in the photoexcited CZNI‐NRs, the initial bound Frenkel excitons are dissociated to long‐lived CSEs after undergoing ultrafast charge transfer within ca. 1.25 ps and charge separation within less than 5.0 ps. Finally, these free electrons were injected into Pt co‐catalysts for reducing protons to H2 at a rate of ca. 417 μmol h−1 g−1, correspondingly an apparent quantum efficiency of ca. 1.3 % can be achieved at 400 nm. [ABSTRACT FROM AUTHOR]

Au nanoparticles (NPs) are dispersively deposited on the explored nonpolar {100} plane of 3D porous ZnO nanosheets (NSs), parallel to the IEF direction. The SPR field parallel to the polar {001} facet, coupling with the IEF. The exciton binding energy can be decreased by the field-field coupling, leading to better charge separation, activity, and selectivity under simulated solar light illumination. • The coupling of plasmonic field and IEF promoted CO 2 photoreduction. • Conversion efficiency of solar-to-hydrocarbon was improved by one order of magnitude. • Au can result in the solar conversion of CO 2 to C 2 H 6 at an amazing selectivity. • The electron phonon decoupling enhanced the PCET process of ZnO nanosheets. • The novel pathway of photocatalytic CO 2 conversion was proposed by DFT. Molecular-level understanding of the solar-driven CO 2 conversion is of importance to design high-efficiency artificial photosynthetic systems for rebalancing the global carbon cycle. Herein, some physical insights into the surface plasmon resonance (SPR) mediated CO 2 photoreduction were demonstrated with metal (Au, Ag, and Pd)/3D porous ZnO nanosheets (NSs). Such plasmonic photocatalysts were designed elaborately to expose the polar {001} facet, based on the physical prototype of field-field coupling, in order to benefit chemical polarization and activation of the inert molecule. Among these plasmonic metals, gold was found to be not only more effective for promoting the solar-driven CO 2 conversion, but unique for producing the higher hydrocarbon, C 2 H 6. A 10-fold enhanced conversion efficiency and a quantum efficiency of 1.03% were achieved on Au/ZnO NSs at ca. 80% selectivity to hydrocarbons under solar light irradiation. The characterization results indicated that the metal-semiconductor interaction enables the electron-phonon decoupling to generate more amounts of energetic electrons in the excited ZnO NSs by a proposed pathway, called the SPR energy transfer induced interband transition that promotes the semiconductor photoexcitation, kinetically accelerating the conversion. Density functional theory calculations revealed that the field-field coupling greatly intensifies the surface polarization for adsorbates, charging negatively the C atom of CO 2 and making O C O bond bent, along with the electrophilic attack by two competitive paths, leading to the concomitance of CO and CH 4. The loading of plasmonic metal nanoparticles alters the molecular paths of CO 2 conversion by tuning thermodynamically the first dehydroxylation step, consequently the product selectivity. Especially Au plasmon, it enables the CO hydrogenation path, making CH 4 faster. [ABSTRACT FROM AUTHOR]

Single‐atom metal‐insulator‐semiconductor (SMIS) heterojunctions based on Sn‐doped Fe2O3 nanorods (SF NRs) were designed by combining atomic deposition of an Al2O3 overlayer with chemical grafting of a RuOx hole‐collector for efficient CO2‐to‐syngas conversion. The RuOx‐Al2O3‐SF photoanode with a 3.0 nm thick Al2O3 overlayer gave a >5‐fold‐enhanced IPCE value of 52.0 % under 370 nm light irradiation at 1.2 V vs. Ag/AgCl, compared to the bare SF NRs. The dielectric field mediated the charge dynamics at the Al2O3/SF NRs interface. Accumulation of long‐lived holes on the surface of the SF NRs photoabsorber aids fast tunneling transfer of hot holes to single‐atom RuOx species, accelerating the O2‐evolving reaction kinetics. The maximal CO‐evolution rate of 265.3 mmol g−1 h−1 was achieved by integration of double SIMS‐3 photoanodes with a single‐atom Ni‐doped graphene CO2‐reduction‐catalyst cathode; an overall quantum efficiency of 5.7 % was recorded under 450 nm light irradiation. [ABSTRACT FROM AUTHOR]

Single‐atom metal‐insulator‐semiconductor (SMIS) heterojunctions based on Sn‐doped Fe2O3 nanorods (SF NRs) were designed by combining atomic deposition of an Al2O3 overlayer with chemical grafting of a RuOx hole‐collector for efficient CO2‐to‐syngas conversion. The RuOx‐Al2O3‐SF photoanode with a 3.0 nm thick Al2O3 overlayer gave a >5‐fold‐enhanced IPCE value of 52.0 % under 370 nm light irradiation at 1.2 V vs. Ag/AgCl, compared to the bare SF NRs. The dielectric field mediated the charge dynamics at the Al2O3/SF NRs interface. Accumulation of long‐lived holes on the surface of the SF NRs photoabsorber aids fast tunneling transfer of hot holes to single‐atom RuOx species, accelerating the O2‐evolving reaction kinetics. The maximal CO‐evolution rate of 265.3 mmol g−1 h−1 was achieved by integration of double SIMS‐3 photoanodes with a single‐atom Ni‐doped graphene CO2‐reduction‐catalyst cathode; an overall quantum efficiency of 5.7 % was recorded under 450 nm light irradiation. [ABSTRACT FROM AUTHOR]

The design and synthesis of two semiconducting bis (4‐ethynyl‐bridging 1, 8‐naphthalimide) bolaamphiphiles (BENI‐COO− and BENI‐NH3+) to fabricate supramolecular metal–insulator–semiconductor (MIS) nanostructures for biomimetic hydrogen evolution under visible light irradiation is presented. A H2 evolution rate of ca. 3.12 mmol g−1⋅h−1 and an apparent quantum efficiency (AQE) of ca. 1.63 % at 400 nm were achieved over the BENI‐COO−‐NH3+‐Ni MIS photosystem prepared by electrostatic self‐assembly of BENI‐COO− with the opposite‐charged DuBois‐Ni catalysts. The hot electrons of photoexcited BENI‐COO− nanofibers were tunneled to the molecular Ni collectors across a salt bridge and an alkyl region of 2.2–2.5 nm length at a rate of 6.10×108 s−1, which is five times larger than the BENI‐NH3+ nanoribbons (1.17×108 s−1). The electric field benefited significantly the electron tunneling dynamics and compensated the charge‐separated states insufficient in the BENI‐COO− nanofibers. [ABSTRACT FROM AUTHOR]

The design and synthesis of two semiconducting bis (4‐ethynyl‐bridging 1, 8‐naphthalimide) bolaamphiphiles (BENI‐COO− and BENI‐NH3+) to fabricate supramolecular metal–insulator–semiconductor (MIS) nanostructures for biomimetic hydrogen evolution under visible light irradiation is presented. A H2 evolution rate of ca. 3.12 mmol g−1⋅h−1 and an apparent quantum efficiency (AQE) of ca. 1.63 % at 400 nm were achieved over the BENI‐COO−‐NH3+‐Ni MIS photosystem prepared by electrostatic self‐assembly of BENI‐COO− with the opposite‐charged DuBois‐Ni catalysts. The hot electrons of photoexcited BENI‐COO− nanofibers were tunneled to the molecular Ni collectors across a salt bridge and an alkyl region of 2.2–2.5 nm length at a rate of 6.10×108 s−1, which is five times larger than the BENI‐NH3+ nanoribbons (1.17×108 s−1). The electric field benefited significantly the electron tunneling dynamics and compensated the charge‐separated states insufficient in the BENI‐COO− nanofibers. [ABSTRACT FROM AUTHOR]

A metal–insulator–semiconductor (MIS) photosystem based on covalent organic framework (COF) semiconductors was designed for robust and efficient hydrogen evolution under visible‐light irradiation. A maximal H2 evolution rate of 8.42 mmol h−1 g−1 and a turnover frequency of 789.5 h−1 were achieved by using a MIS photosystem prepared by electrostatic self‐assembly of polyvinylpyrrolidone (PVP) insulator‐capped Pt nanoparticles (NPs) with the hydrophilic imine‐linked TP‐COFs having =C=O−H−N= hydrogen‐bonding groups. The hot π‐electrons in the photoexcited n‐type TP‐COF semiconductors can be efficiently extracted and tunneled to Pt NPs across an ultrathin PVP insulating layer to reduce protons to H2. Compared to the Schottky‐type counterparts, the COF‐based MIS photosystems give a 32‐fold‐enhanced carrier efficiency, attributed to the combined enhancement of photoexcitation rate, charge separation, and oxidation rate of holes accumulated in the valence band of the TP‐COF semiconductor. [ABSTRACT FROM AUTHOR]

A metal–insulator–semiconductor (MIS) photosystem based on covalent organic framework (COF) semiconductors was designed for robust and efficient hydrogen evolution under visible‐light irradiation. A maximal H2 evolution rate of 8.42 mmol h−1 g−1 and a turnover frequency of 789.5 h−1 were achieved by using a MIS photosystem prepared by electrostatic self‐assembly of polyvinylpyrrolidone (PVP) insulator‐capped Pt nanoparticles (NPs) with the hydrophilic imine‐linked TP‐COFs having =C=O−H−N= hydrogen‐bonding groups. The hot π‐electrons in the photoexcited n‐type TP‐COF semiconductors can be efficiently extracted and tunneled to Pt NPs across an ultrathin PVP insulating layer to reduce protons to H2. Compared to the Schottky‐type counterparts, the COF‐based MIS photosystems give a 32‐fold‐enhanced carrier efficiency, attributed to the combined enhancement of photoexcitation rate, charge separation, and oxidation rate of holes accumulated in the valence band of the TP‐COF semiconductor. [ABSTRACT FROM AUTHOR]

An artificial photosynthetic (APS) system consisting of a photoanodic semiconductor that harvests solar photons to split H2O, a Ni‐SNG cathodic catalyst for the dark reaction of CO2 reduction in a CO2‐saturated NaHCO3 solution, and a proton‐conducting membrane enabled syngas production from CO2 and H2O with solar‐to‐syngas energy‐conversion efficiency of up to 13.6 %. The syngas CO/H2 ratio was tunable between 1:2 and 5:1. Integration of the APS system with photovoltaic cells led to an impressive overall quantum efficiency of 6.29 % for syngas production. The largest turnover frequency of 529.5 h−1 was recorded with a photoanodic N‐TiO2 nanorod array for highly stable CO production. The CO‐evolution rate reached a maximum of 154.9 mmol g−1 h−1 in the dark compartment of the APS cell. Scanning electrochemical–atomic force microscopy showed the localization of electrons on the single‐nickel‐atom sites of the Ni‐SNG catalyst, thus confirming that the multielectron reduction of CO2 to CO was kinetically favored. [ABSTRACT FROM AUTHOR]

An artificial photosynthetic (APS) system consisting of a photoanodic semiconductor that harvests solar photons to split H2O, a Ni‐SNG cathodic catalyst for the dark reaction of CO2 reduction in a CO2‐saturated NaHCO3 solution, and a proton‐conducting membrane enabled syngas production from CO2 and H2O with solar‐to‐syngas energy‐conversion efficiency of up to 13.6 %. The syngas CO/H2 ratio was tunable between 1:2 and 5:1. Integration of the APS system with photovoltaic cells led to an impressive overall quantum efficiency of 6.29 % for syngas production. The largest turnover frequency of 529.5 h−1 was recorded with a photoanodic N‐TiO2 nanorod array for highly stable CO production. The CO‐evolution rate reached a maximum of 154.9 mmol g−1 h−1 in the dark compartment of the APS cell. Scanning electrochemical–atomic force microscopy showed the localization of electrons on the single‐nickel‐atom sites of the Ni‐SNG catalyst, thus confirming that the multielectron reduction of CO2 to CO was kinetically favored. [ABSTRACT FROM AUTHOR]

The work showed the enhancement of NO 2 sensing properties by molecular engineering of oxygen-defect sites in a pyrochlore-phase Pr 2 Zr 2 O 7 oxygen conductor and molecular insights into the oxygen migration pathways by theoretical calculation. A B-site substitution strategy was developed to prepare a series of defective Pr 2 Zr 2-x M x O 7+δ (PZM, M = Al, Ga, In) oxygen conductors to establish the structure-performance relationship of the component-optimized conductors. The structural analysis by the combination of X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and density functional theory calculations clarified the defect-mediated oxygen transport mechanism. The electrochemical results clearly indicate that the thermal-activation energy of oxygen ions increases with the electronegativity of dopants (Al 3+ > Ga 3+ > In 3+ ), independent of the lattice distortion. The In 3+ doping can not only create more amounts of oxygen-defect sites, but also reduce at utmost the bond energy of 48f-oxygen ions in octahedral [ZrO 6 ] units. As a result, the hopping of 48f-oxygen ions can proceed fast across the adjacent oxygen-defect sites as oxygen ion transfer stations. The NO 2 sensing results of the (Pt)NiO/PZM/Pt sensors, which were evaluated at the applied potential of −300 mV in the mild temperature region of 500–700 °C, give a significantly-enhanced Δ I value for the optimized Pr 2 Zr 2-x In x O 7+δ (x = 0.05) conductor, as compared to the pure Pr 2 Zr 2 O 7 counterpart (4.4-fold) and the commercial 8% Y 2 O 3 -ZrO 2 (YSZ) conductor (2.5-fold). The PZM sensor shows the promising application in motor vehicles. [ABSTRACT FROM AUTHOR]

NO 2 sensor has attracted extensive attention due to its important application in environment monitor. Conventional NO 2 sensors based on the yttria-stabilized zirconia (YSZ) electrolyte possess fast response, high sensitivity and good stability, whereas its ionic conductivity decreases significantly at low- and intermediate-temperature, limiting the practical application in motor vehicles. In this work, a pyrochlore-phase A 2 B 2 O 7 solid electrolyte, Pr 2 Zr 2−x Ce x O 7+δ (PZC), was applied for the first time to construct the amperometric-type NO 2 sensor. Ce incorporated significantly improved the sensing performance of the PZC NO 2 sensor with NiO as the sensing electrode. The effect of Ce-doped concentration and operating temperature on the sensitivity, selectivity, stability, response and recovery characteristics were investigated in detail. The results showed that the optimal sensor based on the Pr 2 Zr 1.9 Ce 0.1 O 7+δ substrate gave high sensitivity, excellent selectivity and quick response-recovery behavior to NO 2 gas. The gas-sensing mechanism was also discussed. The PZC sensors are well established effective for sensing NO 2 at mild-temperature working window of 500–700 °C, and thus exhibit the promising application in motor vehicles. [ABSTRACT FROM AUTHOR]

Bacterial infections are a major public health challenge around the world. The development of novel surface coatings that effectively inhibit bacterial adhesion, proliferation and growth is a critical step in addressing this global challenge. Photocatalytic antibacterial therapy has proven to be an effective approach and has received increasing attention. However, it is still a challenge to obtain coatings with both antibacterial adhesion and durable photocatalytic antibacterial functions. Herein, an acridine-based coating with antibacterial adhesion and photocatalytic antibacterial properties was prepared by simple methods (i.e., spin-coating, spray-coating, and drop-coating) and can be applied to various substrates. The bacterial anti-adhesion test results showed that the coating could effectively prevents the adhesion of Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa), indicating the strong anti-fouling capability. The acridine-based coating demonstrated durable photocatalytic antimicrobial activity, remaining 99.3 % antibacterial effective against all three bacterial strains even after 30 days exposed to visible light. The coating can significantly reduce or eliminate the risk of contamination and cross-contamination, making it ideal for use in public healthcare environments. Bacterial infections are a major public health challenge worldwide. The dual-functional acridine-based coatings with anti-bacterial adhesion and durable photocatalytic antibacterial were prepared by simple method (i.e., spin-coating, spray-coating, and drop-coating) and can be applied to various substrates. The coating can significantly reduce or eliminate the risk of contamination and cross-contamination, making it ideal for use in public healthcare environments [Display omitted] • Acridine-based coating has outstanding performance in both anti-bacterial adhesion and bactericidal exhibits. • Acridine-based coating exhibits a durable photocatalytic bactericidal effect of >99.3 % against E. coli , S. aureus , and P. aeruginosa after 30 days. • The acridine-based coating shows satisfactory stability. [ABSTRACT FROM AUTHOR]