N/S co-doped coal-based porous carbon spheres as electrode materials for high performance supercapacitors

N/S co-doped porous carbon spheres (NSPCSs) were prepared by a simple ultrasonic spray pyrolysis (USP) using the mixed solution of coal oxide and l-cysteine, and without a subsequent activation process. The surface properties of carbon materials have been successfully modified by the concurrent incorporation of N and S. So the capacitive performance of NSPCSs was greatly enhanced. It is used as a supercapacitor electrode to achieve a high specific capacitance of 308 F g⁻¹ at a current density of 1 A g⁻¹ and 90.2% capacitance retention even after 10 000 cycles at 5 A g⁻¹. These numerical results show that the supercapacitors based on coal-based carbon materials have great potential in high performance electrochemical energy storage.

N/S co-doped porous carbon spheres were prepared using one step strategy for high performance supercapacitors.     

Si,Sr, Ag co-doped hydroxyapatite/TiO2 coating: enhancement of its antibacterial activity and osteoinductivity

A multifaceted coating with favourable cytocompatibility, osteogenic activity and antibacterial properties would be of great significance and value due to its capability for improving osseointegration and alleviating prosthesis loosening. This study marks the first report on the coating of TiO₂ nanotubular (TNT) arrays with Sr-and-Si-substituted hydroxyapatite (SSHA) endowed with antibacterial characteristics using silver ions. This TNT layer coated with Ag-substituted SSHA (SSAgHA) formed a composite coating with an interconnected microporous structure and a homogeneous distribution of Sr, Si and Ag; such a coating promoted cell adhesion and osteogenic potential. The anchoring effect of the TNT layer improved the adhesion strength of the SSAgHA/TNT coating to 16.9 ± 3.1 MPa, which was higher than the 15 MPa set in the ISO standard 13 779-4:2002. Moreover, the bio-corrosion resistance of the underlying Ti substrate was greatly enhanced by the composite coating. Hydroxyapatite (HA) and SSAgHA coatings provided a suitable environment for the adhesion, spreading and proliferation of mouse osteoblasts. The SSAgHA coating excellently inhibited bacterial activity and enhanced osteoinductivity with higher osteogenic differentiation compared with the HA coating. Sr and Si dopants increased the expression levels of the genes related to osteogenesis and successfully offset the potential cytotoxicity of Ag ions. Super-osteoinductivity was attributed to the rough and superhydrophilic surface of the composite coating. Therefore, the present study demonstrated the potential of the electrodeposited SSAgHA/TNT composite coating as a promising metallic implant with great intrinsic antibacterial activity and osteointegration ability.

A multifaceted coating with favourable cytocompatibility, osteogenic activity and antibacterial properties would be of great significance and value due to its capability for improving osseointegration and alleviating prosthesis loosening.     

N,O and P co-doped honeycomb-like hierarchical porous carbon derived from Sophora japonica for high performance supercapacitors

Novel N, O and P co-doped honeycomb-like hierarchically porous carbon (N-O-P-HHPC) materials with a large specific surface area from Sophora japonica were prepared via a one-step activation and carbonization method and used as an electrode for supercapacitors. The results indicate that as-prepared N-P-HHPC with a large specific surface area (2068.9 m² g⁻¹) and N (1.5 atomic%), O (8.4 atomic%) and P (0.4 atomic%) co-doping has a high specific capacitance of 386 F g⁻¹ at 1 A g⁻¹. Moreover, a 1.8 V symmetrical SC was assembled from the N-O-P-HHPC-3 electrode using 1 M Na₂SO₄ gel electrolyte, presenting a high energy density (28.4 W h kg⁻¹ at 449.9 W kg⁻¹) and a long life cycling stability with only 7.3% capacitance loss after 10 000 cycles. Furthermore, the coin-type symmetrical SC using EMIMBF4 as electrolyte presents an ultrahigh energy density (80.8 W h kg⁻¹ at 1500 W kg⁻¹). When the two coin-type symmetrical SCs are connected in series, eight red light-emitting diodes (LEDs) and a small display screen can be powered. These results demonstrate as-prepared N, O and P co-doped HHPC is a considerable candidate as a carbon electrode for energy storage devices.

N, O and P co-doped honeycomb-like hierarchical porous carbon (N-P-HHPC-3) derived from Sophora japonica displays an ultrahigh energy density (80.8 W h kg⁻¹ at 1500 W kg⁻¹) and outstanding long-term stability.     

A novel multifunctional Ag and Sr2+ co-doped TiO2@rGO ternary nanocomposite with enhanced p-nitrophenol degradation,and bactericidal and hydrogen evolution activity

In the present study, a novel multifunctional Sr²⁺/Ag–TiO₂@rGO ternary hybrid photocatalyst was prepared via facile sol–gel and hydrothermal methods. The prepared catalyst was well characterized by UV-vis, XRD, Raman, HRTEM and XPS. The synthesized composite was utilised for p-NP degradation, E. coli disinfection and H₂ generation under visible light. The Sr²⁺/Ag–TiO₂@rGO catalyst showed enhanced photocatalytic H₂ evolution rate (64.3 μmol h⁻¹) compared with Ag–TiO₂@rGO (30.1 μmol h⁻¹) and TiO₂ (no activity). Nearly complete degradation of 15 mg l⁻¹p-NP was achieved over Sr²⁺/Ag–TiO₂@rGO after 3 h, while only 66% and 5% was achieved by Ag–TiO₂@rGO and TiO₂ respectively. Furthermore, TEM analysis was carried out on Escherichia coli (E. coli) before and after visible light irradiation to understand the inactivation mechanism and DNA analysis indicated no fragmentation during inactivation. Radical quantification experiments and ESR analysis suggested that ·OH and O₂˙⁻ were the main ROS in the degradation and disinfection processes. The superior photocatalytic H₂ evolution rate of Sr²⁺/Ag–TiO₂@rGO was attributed to the synergetic effect between the Ag, Sr²⁺ and TiO₂ components on the rGO surface. The localized SPR effect of Ag induced visible light generated charge carriers into the conduction band of the TiO₂ and Sr²⁺ which further transfer to the rGO for the reduction of H⁺ ions into H₂. The results suggest that Sr²⁺/Ag–TiO₂@rGO structures could not only induce separation and migration efficiency of charge carries, but also improve charge collection efficiency for enhanced catalytic activity. Thus, we believe that this work could provide new insights into multifunctional nanomaterials for applications in solar photocatalytic degradation of harmful organics and pathogenic bacteria with clean energy generation during wastewater treatment.

In the present study, a novel multifunctional Sr²⁺/Ag–TiO₂@rGO ternary hybrid photocatalyst was prepared via facile sol–gel and hydrothermal methods.     

Nitrogen and phosphorus co-doped carbon modified activated carbon as an efficient oxygen reduction catalyst for microbial fuel cells

Activated carbon (AC) is an environmentally sustainable oxygen reduction reaction (ORR) catalyst and widely used in MFCs due to its intrinsic high specific surface area and mesoporous characteristics, but it shows relatively high ORR over-potential thus low electrocatalytic activity. In this study, a method of doped carbon modification was employed to decrease the over-potential and improve the ORR electrocatalytic activity of the AC catalyst. Nitrogen and phosphorus co-doped carbon modified AC (NPC@AC) was prepared by coating phytic acid doped polyaniline onto AC through in situ oxidative polymerization and subsequent high-temperature pyrolysis. The as-prepared NPC@AC possessed a large surface area of ∼649.3 m² g⁻¹ inherited from AC and a low ORR over-potential with a highly positive onset potential of +0.22 V vs. Ag/AgCl from NPC, thus showing an enhanced ORR electrocatalytic activity in neutral solution compared to the pristine AC, and even better than the pure NPC. The air-cathode MFC using the NPC@AC catalyst generated a much higher open circuit voltage of 0.753 V and two times higher power density of 1223 mW m⁻² than that using the pristine AC catalyst of about 0.432 V and 595 mW m⁻², respectively.

Nitrogen and phosphorus co-doped carbon modified activated carbon shows decreased ORR over-potential, thus enhanced ORR electrocatalytic activity in the air-cathode of microbial fuel cells compared to pristine AC.     

Preparation of N/O co-doped porous carbon by a one-step activation method for supercapacitor electrode materials

Heteroatom-doped carbon materials used in supercapacitors are low in cost and demonstrate extraordinary performance. Here, ethylenediamine tetraacetic acid (EDTA) with intrinsic N and O elements is selected as a raw material for the preparation of heteroatom self-doped porous carbon. Furthermore, N/O self-doped porous carbon with a large surface area has been successfully prepared using K₂CO₃ as the activator. The derived sample with a 1 : 2 molar ratio of EDTA to K₂CO₃ (EK-2) demonstrates a porous structure, rich defects, a large surface area of 2057 m² g⁻¹ and a micropore volume of 0.25 cm³ g⁻¹. Benefiting from high N content (2.89 at%) and O content (10.75 at%), EK-2 exhibits superior performance, including high capacitance of 325 F g⁻¹ at 1 A g⁻¹ and outstanding cycling stability with 96.8% retention after 8000 cycles at 10 A g⁻¹, which strongly confirms its immense potential toward many applications. Additionally, the maximum energy density of EK-2 reaches was 17.01 W h kg⁻¹ at a power density of 350 W kg⁻¹ in a two-electrode system. This facile and versatile strategy provides a scalable approach for the batch synthesis of N/O co-doped carbonaceous electrode materials for energy storage.

Heteroatom-doped carbon materials used in supercapacitors are low in cost and demonstrate extraordinary performance.     

N/Fe/Zn co-doped TiO2 loaded on basalt fiber with enhanced photocatalytic activity for organic pollutant degradation

To avoid the loss of catalytic material powder, a loaded catalytic material of TiO₂ with basalt fiber as the carrier (TiO₂@BF) was synthesized by an improved sol–gel method. The TiO₂@BF was doped with different contents of N, Fe and Zn elements and was used to degrade rhodamine B (RhB) under ultraviolet light. The physical characterization analysis indicated that the co-doping of the N, Fe and Zn elements had the effects of reducing grain size, increasing sample surface area, and narrowing the electronic band gap. The electronic band gap of nitrogen–iron–zinc co-doped TiO₂@BF (N/Fe/Zn_TiO₂@BF) was 2.80 eV, which was narrower than that of TiO₂@BF (3.11 eV). The degradation efficiency of RhB with N/Fe/Zn_TiO₂@BF as a photocatalyst was 4.3 times that of TiO₂@BF and its photocatalytic reaction was a first-order kinetic reaction. Quenching experiments suggested that the reactive species mainly include photoinduced holes (h⁺), superoxide radicals (˙O₂⁻) and hydroxyl radicals (˙OH). In brief, this study provides a prospective loaded catalytic material and routine for the degradation of organic contaminants in water by a photocatalytic process.

The photocatalytic activity of N/Fe/Zn_TiO₂@BF, synthesized by a combined sol–gel calcination method, showed great improvement for the degradation of RhB. The reaction mechanism of N/Fe/Zn_TiO₂@BF for the degradation of RhB was proposed.     

Effect of structure regulation of hyper-branched polyester modified carbon nanotubes on toughening performance of epoxy/carbon nanotube nanocomposites

In this paper, carboxylic multi-walled carbon nanotubes (MWCNTs-COOH) were modified by a series of hyperbranched polyesters (HBP) with different molecular structures (different branching degree) through surface grafting, and then the epoxy resin (EP)/carbon nanotube composites were prepared to explore the influences of structure regulation of HBP modified carbon nanotubes on the toughening performance of the composites. The results of Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA) of various HBP grafted carbon nanotubes confirmed that the HBP were successfully grafted onto MWCNTs-COOH via an esterification reaction between the carboxyl groups of MWCNTs-COOH and the hydroxyl groups of HBP, meanwhile, the higher the branching degree of the HBP, the higher its grafting ratio onto carbon nanotubes. Furthermore, the outcome of dynamic thermal mechanical analysis (DMA) indicated that the addition of MWCNTs-COOH increased the storage modulus and glass transition temperature (T_g) of the pure EP, and surface grafting of various HBP onto MWCNTs-COOH decreased the T_g and peak height of mechanical loss of composites. And as the branching degree of HBP increased, the interfacial bonding between MWCNTs and the EP matrix became stronger. The results of mechanical performance and morphology analysis also revealed that the addition of HBP grafted MWCNTs-COOH significantly improved its dispersion and interfacial bonding in the EP matrix, resulting in better performance in the enhancement of toughness of the composites. In addition, it was found that the higher the branching degree of HBP, the better the toughening performance of the composites.

Carboxylic carbon nanotubes were modified by a series of hyperbranched polyesters (HBP), and epoxy resin/carbon nanotubes composites were prepared. The effect of structure regulation of HBP on toughening properties of composites was discussed.     

Nitrogen and sulfur co-doped cobalt carbon catalysts for ethylbenzene oxidation with synergistically enhanced performance

Heteroatom doping has been demonstrated to be an effective strategy for improving the performance of catalysts. In this paper, cobalt carbon catalysts co-doped with nitrogen and sulfur (N and S) were synthesized through a hydrothermal method with chelate composites involving melamine, thioglycolic acid (C₂H₄O₂S), and tetrahydrate cobalt acetate (Co(OAc)₂·4H₂O). In addition, the selective oxidation of ethylbenzene under solvent-free conditions with molecular oxygen was used as a probe reaction to evaluate the activity of the catalysts. The optimized catalyst shows an ethylbenzene conversion of 48% with an acetophenone selectivity of 85%. Furthermore, the catalysts were systematically characterized by techniques such as TEM, SEM, XRD, Raman, and XPS. The results reveal that the species of cobalt sulfides and synergistic effects between N and S has inserted a key influence on their catalytic performance.

Co-N-S-C catalysts with rod-like structures were synthesized for the selective oxidation of ethylbenzene using O₂ as an oxidant.     

Enhanced dielectric properties of colossal permittivity co-doped TiO2/polymer composite films

Colossal permittivity (CP) materials have shown great technological potential for advanced microelectronics and high-energy-density storage applications. However, developing high performance CP materials has been met with limited success because of low breakdown electric field and large dielectric loss. Here, composite films have been developed based on surface hydroxylated ceramic fillers, (Er + Nb) co-doped TiO₂ embedded in poly(vinylidene fluoride trifluoroethylene) matrix by a simple technique. We report on simultaneously observing a large dielectric constant up to 300, exceptional low dielectric loss down to 0.04 in the low frequency range, and an acceptable breakdown electric field of 813 kV cm⁻¹ in the composites. Consequently, this work may pave the way for developing highly stable and superior dielectrics through a simple and scalable route to meet requirements of further miniaturization in microelectronic and energy-storage devices.

Colossal permittivity (CP) materials have shown great technological potential for advanced microelectronics and high-energy-density storage applications.     

Enhanced photocatalytic performance of carbon fiber paper supported TiO2 under the ultrasonic synergy effect

In the present work, TiO₂ rutile nanorods and anatase nanoflakes have been grown on carbon fiber paper (CFP) by the hydrothermal method. Their photoelectrochemical properties and photocatalytic performances have been investigated. The introduction of CFP is found to improve visible light absorption intensity and effective surface areas apparently, and also make TiO₂ photocatalysts easier to recycle from aqueous waste. An ultrasonic field was employed during the process of photocatalysis. Sono-photocatalytic efficiency is found to be enhanced significantly in comparison with those of photocatalysis and sonocatalysis, which indicates a positive ultrasonic synergy effect. The scavenger experiments reveal that superoxide radicals (˙O₂⁻) and hydroxyl (˙OH) are the predominant active species during the dye degradation sono-photocatalytic process assisted by CFP-supported TiO₂ catalysts. To investigate the ultrasonic synergy photocatalytic effect, the generated amount of reactive oxygen species (ROS) was detected and quantitatively evaluated under visible light, ultrasound, and the combined condition of visible light and ultrasound. As a result, the present work provides an efficient way to improve photocatalytic performance and to realize easy recovery of photocatalyst, which will be helpful for better design of advanced photocatalysts for practical applications.

SEM images of TiO₂(R) nanorods and TiO₂(A) nanoflakes grown on CFP. And the corresponding catalytic performances under solely visible light, solely ultrasonic field, and the combined conditions of visible light and ultrasonic field.     

Efficient detoxification of triclosan by a S–Ag/TiO2@g-C3N4 hybrid photocatalyst: process optimization and bio-toxicity assessment

Owing to their persistency and toxicity, development of an effective strategy to eliminate antibiotic residues from the aquatic system has become a major environmental concern. Doping TiO₂ with hetero atoms and forming a hybrid structure with g-C₃N₄ could serve as an efficient visible light active photocatalytic candidate. In this study, a novel S–Ag/TiO₂@g-C₃N₄ hybrid catalyst was prepared for visible light degradation and detoxification of triclosan (TS) antibiotic. The effect of various operational parameters towards the photocatalytic degradation was systematically evaluated through response surface methodology (RSM) based on central composite design (CCD). The highest TS degradation (92.3%) was observed under optimal conditions (TS concentration = 10 mg L⁻¹, pH = 7.8, and catalyst weight = 0.20 g L⁻¹) after 60 min. Efficient charge separation resulted from the doped nanoparticles (silver and sulphur), the existing integrated electric field of the heterojunction and the overlying light response of hybridized TiO₂ and g-C₃N₄, thus the S–Ag/TiO₂@g-C₃N₄ composite showed impressively higher activity. The main degradation products of TS were identified by LC/ESI-MS analysis. In addition, the toxicity of the degradation products was investigated through an Escherichia coli (E. coli) colony forming unit assay and the results revealed that under optimal conditions a significant reduction in biotoxicity was noticed.

Owing to their persistency and toxicity, development of an effective strategy to eliminate antibiotic residues from the aquatic system has become a major environmental concern.     

Supercapacitive performance of TiO2 boosted by a unique porous TiO2/Ti network and activated Ti3+

TiO₂ has been reported to have considerable capacity through appropriate surface modification. Previous studies of TiO₂-based supercapacitors mainly focused on anodized TiO₂ nanotubes and TiO₂ powder, even though the capacitance still lags behind that of carbon-base materials. In this work, a three-dimensional porous TiO₂/Ti (PTT) network was constructed by anodic oxidation and its capacitance was boosted by subsequent aluminum-reduction process. Activated Ti³⁺ was proved to be being successfully introduced into the surface of pristine PTT, resulting in the prominent enhancement of supercapacitive performance. An areal capacitance of 81.75 mF cm⁻² was achieved from Al-reduced PTT (Al-PTT) at 500 °C in 1 M H₂SO₄ electrolyte, which was among the highest value of pure TiO₂-based electrodes. Good electrochemical stability was also confirmed by the 3.12% loss of the highest capacity after 5000 CV cycles. More importantly, the activated Ti³⁺/Ti⁴⁺ redox couple in modified TiO₂ is solidly confirmed by being directly observed in CV curves. The capacitive mechanism of the redox reaction is also studied by electrochemical tests. The construction of a 3D porous network structure and efficient Ti³⁺ introduction provide an effective method to boost the supercapacitive performance of TiO₂-based materials for energy storage applications.

Excellent supercapacitive performance is achieved by constructing a 3D porous TiO₂/Ti network structure and introducing an activated Ti³⁺/Ti⁴⁺ redox couple.     

Plasmonic enhanced photocatalytic activity of Ag/TiO2 tube-in-tube fibers

Ag nanoparticle was found to significantly enhance the photocatalytic activity of self-organized TiO₂ nanotube structures. Herein, novel Ag/TiO₂ tube-in-tube fibers have been prepared by a facile electrospinning technology and calcination process. Employed as the photocatalyst, the composite could efficiently catalyze the photodegradation of the model organic pollutant, rhodamine B under visible light irradiation, exhibiting a superior photocatalytic activity than the undoped TiO₂ tube-in-tube fibers. This enhanced activity has been ascribed to plasmonic characteristics of Ag nanoparticles, which promote the light absorption and charge transfer feasibility. The simple, low-cost and green fabrication route of the composite provides a novel means for preparing similar materials, holding great promise for wider application in the future.

Ag nanoparticle was found to significantly enhance the photocatalytic activity of self-organized TiO₂ nanotube structures.     

Electrochemical performance of myoglobin based on TiO2-doped carbon nanofiber decorated electrode and its applications in biosensing

A new biosensing strategy based on a TiO₂-doped carbon nanofiber (CNF) composite modified electrode was developed. TiO₂@CNF was prepared by electrospinning with further carbonization, before being characterized by various methods and used for electrode modification on the surface of carbon ionic liquid electrode (CILE). Myoglobin (Mb) was further immobilized on the modified electrode surface. The results of ultraviolet-visible (UV-vis) and Fourier transform infrared (FT-IR) spectroscopy showed that Mb maintained its native structure without denaturation in the composite film. Direct electron transfer and the electrocatalytic properties of Mb on the electrode surface were further investigated. A pair of quasi-reversible redox peaks appeared on the cyclic voltammogram, indicating that direct electrochemistry of Mb was realized in the nanocomposite film. This could be attributed to the specific properties of TiO₂@CNF nanocomposite, including a large surface-to-volume ratio, good biocompatibility and high conductivity. Nafion/Mb/TiO₂@CNF/CILE exhibited an excellent electrochemical catalytic ability in the reduction of trichloroacetic acid, NaNO₂ and H₂O₂. All results demonstrated potential applications of TiO₂@CNF in third-generation electrochemical biosensors.

A new biosensing strategy based on a TiO₂-doped carbon nanofiber (CNF) composite modified electrode was developed.     

Reducing the barrier effect of graphene sheets on a Ag cocatalyst to further improve the photocatalytic performance of TiO2

Graphene-based cocatalysts can improve the photocatalytic properties of semiconductors, but sometimes, they also function as barrier-like materials, influencing the photoactivity of composites. However, in a multi-cocatalyst system, less attention is paid to these negative effects of graphene on the performance of other cocatalysts. In this study, by adjusting the loading sequence of graphene and Ag cocatalyst on the surface of TiO₂ spheres, the barrier effect of graphene sheets on Ag nanoparticles could be controlled effectively. As a result, these ternary composites with almost no Ag nanoparticles wrapped by graphene possessed improved properties for the photocatalytic reduction of nitro-aromatics as compared to those with some Ag nanoparticles covered by graphene. Furthermore, this phenomenon of barrier effect caused by graphene could be found in the control reaction with metal silver as the main catalyst; this indicated that by avoiding the possible negative influence of graphene on other cocatalysts, the properties of composites with graphene-containing multi cocatalysts could be further improved.

By avoiding the possible barrier influence of graphene on other cocatalysts, the photocatalytic properties of the composites containing multi-cocatalysts could be further improved.     

Black TiO2 nanotube arrays fabricated by electrochemical self-doping and their photoelectrochemical performance

Herein, black TiO₂ nanotube arrays (NTAs) were fabricated using electrochemical self-doping approaches, and characterized systemically by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), UV-visible absorption spectroscopy and photoluminescence spectroscopy (PL). The as-obtained black TiO₂ nanotube arrays (NTAs) exhibited stronger absorption in the visible-light region, a better separation rate of light-induced carriers, and higher electrical conductivity than TiO₂ nanotube arrays (NTAs). These characteristics cause black TiO₂ nanotube array (NTA) electrodes to have higher photoelectrocatalytic activity for degrading anthraquinone dye (reactive brilliant blue KN-R) than the TiO₂ nanotube array (NTA) electrode. Furthermore, a synergetic action between photocatalysis and electrocatalysis was also observed. The black TiO₂ nanotube array (NTA) electrode is considered to be a promising photoanode for the treatment of organic pollutants.

It was found that the removal of KN-R on black TiO₂ NTAs electrodes can be improved by combination of electro-enhanced photocatalysis and electrochemical oxidation at high bias.     

Rapid and selective electrochemical transformation of ammonia to N2 by substoichiometric TiO2-based electrochemical system

In this study, we have developed a continuous-flow electrochemical system towards the rapid and selective conversion of ammonia to N₂, based on a tubular substoichiometric titanium dioxide (Ti₄O₇) anode and a Pd–Cu co-modified Ni foam (Pd–Cu/NF) cathode, both of which are indispensable. Under the action of a suitable anode potential, the Ti₄O₇ anode enables the conversion of Cl⁻ to chloride radicals (Cl˙), which could selectively react with ammonia to produce N₂. The anodic byproducts, e.g. NO₃⁻, were further reduced to N₂ at the Pd–Cu/NF cathode. EPR and scavenger experiments confirmed the dominant role of Cl˙ in ammonia conversion. Complete transformation of 30 mg L⁻¹ ammonia could be obtained over 40 min of continuous operation under optimal conditions. The proposed electrochemical system also exhibits enhanced oxidation kinetics compared to conventional batch systems. This study provides new insights into the rational design of a high-performance electrochemical system to address the challenging issue of ammonia pollution.

A continuous-flow electrochemical system for rapid and selective conversion of ammonia to N₂ was proposed. The system consists of a tubular substoichiometric titanium dioxide (Ti₄O₇) anode and a Pd–Cu co-modified Ni foam (Pd–Cu/NF) cathode.     

Enhanced photoelectrochemical performance of TiO2 nanorod array films based on TiO2 compact layers synthesized by a two-step method

An innovative two-step method perfectly prepared TCLs with different thicknesses, and then the TNA films based on TCLs were successfully prepared. The effects of different thicknesses of TCLs on the morphology and photoelectrochemical performance of TNA films were investigated. The results indicated that TCLs with appropriate thickness could effectively improve the morphology and photoelectrochemical performance of TNA films. Compared with the TNA films based on TCL₅, TCL₁₀ and TCL₃₀, the TNA film based on TCL₂₀ exhibited more ideal and comprehensive photoelectrochemical performance. Moreover, dye-sensitized solar cells (DSSCs) based on this TNA film achieved the highest J_sc (10.2054 mA cm⁻²), V_oc (0.5737 V), PCE (3.3%) and P_out (3.31 mW cm⁻²).

An innovative two-step method perfectly prepared TCLs with different thicknesses, and then the TNA films based on TCLs were successfully prepared.     

Facile construction of Fe,N and P co-doped carbon spheres by carbothermal strategy for the adsorption and reduction of U(vi)

In this work, nitrogen and phosphorus co-doped magnetic carbon spheres encapsulating well-dispersed active Fe nanocrystals (Fe/P-CN) were fabricated via a simple copolymer pyrolysis strategy. Benefiting from heteroatoms doping, Fe/P-CN could primarily adsorb soluble U(vi) ions through abundant functional groups, and subsequently, the adsorbed U(vi) could be reduced to insoluble U(iv) by Fe nanocrystals. Fe/P-CN pyrolyzed at 800 °C (Fe/P-CN-800) exhibited excellent U(vi) removal capacity of 306.76 mg g⁻¹, surpassing nitrogen and phosphorus co-doped carbon spheres and nano zero-valent iron. In addition, the magnetic separation and thermal reactivation properties endow Fe/P-CN-800 with excellent reusability. This research, especially, provides a promising synergistic adsorption and reduction strategy to effectively remove U(vi) using heteroatom-doped composites.

The constructed novel magnetic carbon sphere co-doped by N, P, Fe (Fe/P-CN) exhibits high U(vi) removal efficiency, excellent magnetic separation and reusability, evidencing the potential practical applications in environmental remediation.