Ultrasound-Triggered Piezoelectric Catalysis of Zinc Oxide@Glucose Derived Carbon Spheres for the Treatment of MRSA Infected Osteomyelitis.

Currently, methicillin-resistant Staphylococcus aureus (MRSA)-induced osteomyelitis is a clinically life-threatening disease, however, long-term antibiotic treatment can lead to bacterial resistance, posing a huge challenge to treatment and public health. In this study, glucose-derived carbon spheres loaded with zinc oxide (ZnO@HTCS) are successfully constructed. This composite demonstrates the robust ability to generate reactive oxygen species (ROS) under ultrasound (US) irradiation, eradicating 99.788% ± 0.087% of MRSA within 15 min and effectively treating MRSA-induced osteomyelitis infection. Piezoelectric force microscopy tests and finite element method simulations reveal that the ZnO@HTCS composite exhibits superior piezoelectric catalytic performance compared to pure ZnO, making it a unique piezoelectric sonosensitizer. Density functional theory calculations reveal that the formation of a Mott-Schottky heterojunction and an internal piezoelectric field within the interface accelerates the electron transfer and the separation of electron-hole pairs. Concurrently, surface vacancies of the composite enable the adsorption of a greater amount of oxygen, enhancing the piezoelectric catalytic effect and generating a substantial quantity of ROS. This work not only presents a promising approach for augmenting piezoelectric catalysis through construction of a Schottky heterojunction interface but also provides a novel, efficient therapeutic strategy for treating osteomyelitis.

A Smart Bacteria-Capture-Killing Vector for Effectively Treating Osteomyelitis Through Synergy Under Microwave Therapy.

Osteomyelitis caused by deep tissue infections is difficult to cure through phototherapy due to the poor penetration depth of the light. Herein, Cu/C/Fe3O4-COOH nanorod composites (Cu/C/Fe3O4-COOH) with nanoscale tip convex structures are successfully fabricated as a microwave-responsive smart bacteria-capture-killing vector. Cu/C/Fe3O4-COOH exhibited excellent magnetic targeting and bacteria-capturing ability due to its magnetism and high selectivity affinity to the amino groups on the surface of Staphylococcus aureus (S. aureus). Under microwave irradiation, Cu/C/Fe3O4-COOH efficiently treated S. aureus-infected osteomyelitis through the synergistic effects of microwave thermal therapy, microwave dynamic therapy, and copper ion therapy. It is calculated the electric field intensity in various regions of Cu/C/Fe3O4-COOH under microwave irradiation, demonstrating that it obtained the highest electric field intensity on the surface of copper nanoparticles of Cu/C/Fe3O4-COOH due to its high-curvature tips and metallic properties. This led to copper nanoparticles attracted more charged particles compared with other areas in Cu/C/Fe3O4-COOH. These charges are easier to escape from the high curvature surface of Cu/C/Fe3O4-COOH, and captured by adsorbed oxygen, resulting in the generation of reactive oxygen species. The Cu/C/Fe3O4-COOH designed in this study is expected to provide insight into the treatment of deep tissue infections under the irradiation of microwave.

Natural Extracts for Antibacterial Applications.

Bacteria-induced epidemics and infectious diseases are seriously threatening the health of people around the world. In addition, antibiotic therapy has been inducing increasingly more serious bacterial resistance, which makes it urgent to develop new treatment strategies to combat bacteria, including multidrug-resistant bacteria. Natural extracts displaying antibacterial activity and good biocompatibility have attracted much attention due to greater concerns about the safety of synthetic chemicals and emerging drug resistance. These antibacterial components can be isolated and utilized as antimicrobials, as well as transformed, combined, or wrapped with other substances by using modern assistive technologies to fight bacteria synergistically. This review summarizes recent advances in natural extracts from three kinds of sources-plants, animals, and microorganisms-for antibacterial applications. This work discusses the corresponding antibacterial mechanisms and the future development of natural extracts in antibacterial fields.

Electron Aggregation and Oxygen Fixation Reinforced Microwave Dynamic and Thermal Therapy for Effective Treatment of MRSA-Induced Osteomyelitis.

Antibiotics are frequently used to clinically treat osteomyelitis caused by bacterial infections. However, extended antibiotic use may result in drug resistance, which can be life threatening. Here, a heterojunction comprising Fe2 O3 /Fe3 S4 magnetic composite is constructed to achieve short-term and efficient treat osteomyelitis caused by methicillin-resistant Staphylococcus aureus (MRSA). The Fe2 O3 /Fe3 S4 composite exhibits powerful microwave (MW) absorption properties, thereby effectively converting incident electromagnetic energy into thermal energy. Density functional theory calculations demonstrate that Fe2 O3 /Fe3 S4 possesses significant charge accumulation and oxygen-fixing capacity at the heterogeneous interface, which provides more active sites and oxygen sources for trapping electromagnetic hotspots. The finite element analysis indicates that Fe2 O3 /Fe3 S4 displays a larger electromagnetism field enhancement parameter than Fe2 O3 owing to a significant increase in electromagnetic hotspots. These hotspots contribute to charge differential accumulation and depletion motions at the interface, thereby augmenting the release of free electrons that subsequently combine with the oxygen adsorbed by Fe2 O3 /Fe3 S4 to generate reactive oxygen species (ROS) and heat. This research, which achieves extraordinary bacterial eradication through the synergistic effect of microwave thermal therapy (MWTT) and microwave dynamic therapy (MDT), presents a novel strategy for treating deep-tissue bacterial infections.

Epidemiology, clinical presentation, pathophysiology, and management of long COVID: an update.

The increasing number of coronavirus disease 2019 (COVID-19) infections have highlighted the long-term consequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection called long COVID. Although the concept and definition of long COVID are described differently across countries and institutions, there is general agreement that it affects multiple systems, including the immune, respiratory, cardiovascular, gastrointestinal, neuropsychological, musculoskeletal, and other systems. This review aims to provide a synthesis of published epidemiology, symptoms, and risk factors of long COVID. We also summarize potential pathophysiological mechanisms and biomarkers for precise prevention, early diagnosis, and accurate treatment of long COVID. Furthermore, we suggest evidence-based guidelines for the comprehensive evaluation and management of long COVID, involving treatment, health systems, health finance, public attitudes, and international cooperation, which is proposed to improve the treatment strategies, preventive measures, and public health policy making of long COVID.

The phenotype and prediction of long-term physical, mental and cognitive COVID-19 sequelae 20 months after recovery, a community-based cohort study in China.

Long-term sequelae clustering phenotypes are important for precise health care management in COVID-19 survivors. We reported findings for 1000 survivors 20 months after diagnosis of COVID-19 in a community-based cohort in China. Sequelae symptoms were collected from a validated questionnaire covering 27 symptoms involved in five organ systems including self-reported physical condition, dyspnea, cognitive function and mental health. The generalized symptoms were reported with the highest rate (60.7%), followed by the mental (48.3%), cardiopulmonary (39.8%), neurological (37.1%; cognitive impairment, 15.6%), and digestive symptoms (19.1%). Four clusters were identified by latent class analysis: 44.9% no or mild group (cluster 1), 29.2% moderate group with mainly physical impairment (cluster 2), 9.6% moderate group with mainly cognitive and mental health impairment (cluster 3), and 16.3% severe group (cluster 4). Physical comorbidities or history of mental disorders, longer hospitalization periods and severe acute illness predicted severe group. For moderate group, adults less than 60 years, with physical comorbidities and severe acute illness were more likely to have physical symptoms, while adult women with longer hospitalization stays had increased risk of cognitive and mental health impairment. Overall, among more than half of community COVID-19 survivors who presented moderate or severe sequelae 20 months after recovery, three-tenth had physical vulnerability that may require physical therapy aiming to improve functioning, one-tenth mental or cognitive vulnerable cases need psychotherapy and cognitive rehabilitation, and one-sixth severe group needs multidisciplinary clinical management. The remaining half is free to clinical intervention. Our findings introduced an important framework to map numerous symptoms to precise classification of the clinical sequelae phenotype and provide information to guide future stratified recovery interventions.

Dual Redox Reaction Sites for Pseudocapacitance Based on Ti and -P Functional Groups of Ti3C2PBrx MXene.

MXenes have extensive applications due to their different properties determined by intrinsic structures and various functional groups. Exploring different functional groups of MXenes leads to improved performance or potential applications. In this work, we prepared new Ti3C2PBrx (x=0.4-0.6) MXene with phosphorus functional groups (-P) through a two-step gas-phase reaction. The acquisition of -P is achieved by replacing bromine functional groups (-Br) of Ti3C2Br2 in the phosphorus vapor. After -Br is replaced with -P, Ti3C2PBrx MXene shows an improved areal capacitance (360 mF cm-2) at 20 mV s-1 compared with Ti3C2Br2 MXene (102 mF cm-2). At a current density of 5 mA cm-2 after 10000 cycles, the capacitance retention of Ti3C2PBrx MXene has not decreased. The pseudocapacitive enhancement mechanism has been discovered based on the dual redox sites of the functional groups -P and Ti.

Ultrasound-Responsive Microneedles Eradicate Deep-Layered Wound Biofilm Based on TiO2 Crystal Phase Engineering.

Wound biofilm infection has an inherent resistance to antibiotics, requiring physical debridement combined with chemical reagents or antibiotics in clinical treatment, but it is invasive and may exist as incomplete debridement. So, a new type of noninvasive and efficient treatment is needed to address this problem. Here, the crystal phase engineering of TiO2 is presented to explore the sonocatalytic properties of TiO2 nanoparticles with different phases, and find that the anatase-brookite TiO2  (AB) has the best antibacterial efficiency of 99.94% against S. aureus under 15 min of ultrasound (US) irradiation. The type II homojunction of AB not only enhances the adsorption and decreases the activation energy of O2 , respectively, but also has a great interfacial charge transfer efficiency under US, which can produce more reactive oxygen species than other types of TiO2 . The microneedles (MN) penetrate the biofilm in wound tissue and quickly disperse the loaded AB into the biofilm because the ultrasonic cavitation accelerates the dissolution of microneedles, which non-invasively and efficiently eradicates the deep-layered biofilm under US. This work explores the relationship between the phase composition of TiO2 and sonocatalytic property for the first time, and provides a new treatment strategy for wound biofilm infection through US-assisted microneedles therapy.

Metal Ion Coordination Improves Graphite Nitride Carbon Microwave Therapy in Antibacterial and Osteomyelitis Treatment.

The ability to effectively treat deep bacterial infections while promoting osteogenesis is the biggest treatment demand for diseases such as osteomyelitis. Microwave therapy is widely studied due to its remarkable ability to penetrate deep tissue. This paper focuses on the development of a microwave-responsive system, namely, a zinc ion (Zn2+ ) doped graphite carbon nitride (CN) system (BZCN), achieved through two high-temperature burning processes. By subjecting composite materials to microwave irradiation, an impressive 99.81% eradication of Staphylococcus aureus is observed within 15 min. Moreover, this treatment enhances the growth of bone marrow stromal cells. The Zn2+ doping effectively alters the electronic structure of CN, resulting in the generation of a substantial number of free electrons on the material's surface. Under microwave stimulation, sodium ions collide and ionize with the free electrons generated by BZCN, generating a large amount of energy, which reacts with water and oxygen, producing reactive oxygen species. In addition, Zn2+ doping improves the conductivity of CN and increases the number of unsaturated electrons. Under microwave irradiation, polar molecules undergo movement and generate frictional heat. Finally, the released Zn2+ promotes macrophages to polarize toward the M2 phenotype, which is beneficial for tibial repair.

Engineering Dynamic Defect of CeIII /CeIV -Based Metal-Organic Framework through Ultrasound-Triggered Au Electron Trapper for Sonodynamic Therapy of Osteomyelitis.

Defect engineering is an important way to tune the catalytic properties of metal-organic framework (MOF), yet precise control of defects is difficult to achieve. Herein, a cerium-based MOF (CeTCPP) is decorated with Au nanoparticles. Under ultrasound irradiation, Au nanoparticles can precisely turn 1/3 of the pristine Ce3+ nodes into Ce4+ . With the stable existence of Ce4+ , the coordination of Ce nodes changed, causing the structural irregularity in CeTCPP-Au, so that the electron-hole recombination is obviously hindered, facilitating the generation of reactive oxygen species. Therefore, under 20 min of ultrasound irradiation, the CeTCPP-Au showed superior antibacterial efficacy of over 99% against Staphylococcus aureus and Escherichia coli with good biocompatibility, which is further used for effective therapy of osteomyelitis. Overall, this work provides a dynamic defect formation strategy of MOF through the electron trapping of Au nanoparticles, which also sheds light on sonodynamic therapy in curing deep-seated lesions.

Metal organic framework-based antibacterial agents and their underlying mechanisms.

Bacteria, as the most abundant living organisms, have always been a threat to human life until the development of antibiotics. However, with the wide use of antibiotics over a long time, bacteria have gradually gained tolerance to antibiotics, further aggravating threat to human beings and environmental safety significantly. In recent decades, new bacteria-killing methods based on metal ions, hyperthermia, free radicals, physical pricks, and the coordination of several multi-mechanisms have attracted increasing attention. Consequently, multiple types of new antibacterial agents have been developed. Among them, metal organic frameworks (MOFs) appear to play an increasingly important role. The unique characteristics of MOFs make them suitable multiple-functional platforms. By selecting the appropriate metastable coordination bonds, MOFs can act as reservoirs and release antibacterial metal ions or organic linkers; by constructing a porous structure, MOFs can act as carriers for multiple types of agents and achieve slow and sustained release; and by designing their composition and the pore structure precisely, MOFs can be endowed with properties to produce heat and free radicals under stimulation. Importantly, in combination with other materials, MOFs can act as a platform to kill bacteria effectively through the synergistic effect of multiple types of mechanisms. In this review, we focus on the recent development of MOF-based antibacterial agents, which are classified according to their antibacterial mechanisms.

Alloying-Triggered Phase Engineering of NiFe System via Laser-Assisted Al Incorporation for Full Water Splitting.

It is challenging to design one non-noble material with balanced bifunctional performance for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) for commercial sustainability at a low cost since the different electrocatalytic mechanisms are not easily matchable for each other. Herein, a self-standing hybrid system Ni18 Fe12 Al70 , consisting of Ni2 Al3 and Ni3 Fe phases, was constructed by laser-assisted aluminum (Al) incorporation towards full water splitting. It was found that the incorporation of Al could effectively tune the morphologies, compositions and phases. The results indicate that Ni18 Fe12 Al70 delivers an extremely low overpotential to trigger both HER (η100 =188 mV) and OER (η100 =345 mV) processes and maintains a stable overpotential for 100 h, comparable to state-of-the-art electrocatalysts. The synergistic effect of Ni2 Al3 and Ni3 Fe alloys on the HER process is confirmed based on theoretical calculation.

Oxygen Vacancies-Rich Heterojunction of Ti3 C2 /BiOBr for Photo-Excited Antibacterial Textiles.

Pathogenic bacteria that adhere on the surface of textiles, especially healthcare workers' uniforms, have brought severe problems, including nosocomial infection and other infectious diseases. Here, antibacterial textiles are fabricated by in situ growing oxygen vacancies (OVs) BiOBr on the surface of Ti3 C2 nanosheets followed by in situ polymerization of polypyrrole (ppy). The formed Schottky heterojunction containing OVs of Ti3 C2 /BiOBr effectively enhance the transfer and separation of photogenerated carriers, inhibit the recombination, and decrease the band gap by introducing defect level, which significantly improve the photocatalytic activity, leading to higher reactive oxygen species (ROS) under light irradiation. Therefore, the antibacterial efficacy of textiles reaches up to 98.64% against Staphylococcus aureus and 99.89% against Escherichia coli with the assistance of hyperthermia under light irradiation for 15 min. This work provides insights for designing photo-excited antibacterial textiles by interfacial construction based on Schottky junctions and OVs in the incorporated nanomaterials.

Regulation of Macrophage Polarization Through Periodic Photo-Thermal Treatment to Facilitate Osteogenesis.

The richened reactive oxygen species (ROS) and their derived excessive inflammation at bone injured sites hinder osteogenesis of endosseous Ti-based implants. Herein, anti-oxidized polydopamine (PDA) is deposited on hydrothermal growth formed hydroxyapatite (HA) nanorods on Ti to form a core-shell structural nanorod-like array with HA as a core and PDA as an amorphous shell (PDA@HA), showing not only ROS scavenging ability but also near-infrared (NIR) light derived photo-thermal effects. PDA@HA suppresses inflammation based on its ROS scavenging ability to a certain extent, while periodic photo-thermal treatment (PTT) at a mild temperature (41 ± 1 °C) further accelerates the transition of the macrophages (MΦs) adhered to PDA@HA from the pro-inflammatory (M1) phenotype to the anti-inflammatory (M2) phenotype in vitro and in vivo. Transcriptomic analysis reveals that the activation of the PI3K-Akt1 signaling pathway is responsible for the periodic PTT induced acceleration of the M1-to-M2 transition of MΦs. Acting on mesenchymal stem cells (MSCs) with paracrine cytokines of M2 macrophages, PDA@HA with mild PTT greatly promote the osteogenetic functions of MSCs and thus osteogenesis. This work paves a way of employing mildly periodic PTT to induce a favorable immunomodulatory microenvironment for osteogenesis and provides insights into its underlying immunomodulation mechanism.

Magnetic Composite Rapidly Treats Staphylococcus aureus-Infected Osteomyelitis through Microwave Strengthened Thermal Effects and Reactive Oxygen Species.

It is difficult to effectively treat bacterial osteomyelitis using photothermal therapy or photodynamic therapy due to poor penetration of light. Here, a microwave (MW)-excited magnetic composite of molybdenum disulfide (MoS2 ) / iron oxide (Fe3 O4 ) is reported for the treatment of bacteria-infected osteomyelitis. In in vitro and in vivo experiments, MoS2 /Fe3 O4 is shown to effectively eradicate bacteria-infected mouse tibia osteomyelitis, due to MW thermal enhancement and reactive oxygen species (ROS) (1 O2 and ·O2 - ) production under MW radiation. In addition, the mechanism of MW heat generation is proposed by MW network vector analysis. By the density functional theory and finite element method, the ROS generation mechanism is proposed. The synergy or conductive network between dielectric MoS2 and magnetic Fe3 O4 can reach both enhancement of the dielectric and magnetic attenuation capability. In addition, abundant interfaces are generated to enhance the attenuation of electromagnetic waves by MoS2 and Fe3 O4, introducing multiple reflections and interfacial polarization. Therefore, MoS2 /Fe3 O4 has excellent MW absorption ability based on the synergy or conductive network between MoS2 and magnetic Fe3 O4 as well as multiple dielectric reflections and interfacial polarization.

The recent progress on metal-organic frameworks for phototherapy.

Some infectious or malignant diseases such as cancers are seriously threatening the health of human beings all over the world. The commonly used antibiotic therapy cannot effectively treat these diseases within a short time, and also bring about adverse effects such as drug resistance and immune system damage during long-term systemic treatment. Phototherapy is an emerging antibiotic-free strategy to treat these diseases. Upon light irradiation, phototherapeutic agents can generate cytotoxic reactive oxygen species (ROS) or induce a temperature increase, which leads to the death of targeted cells. These two kinds of killing strategies are referred to as photodynamic therapy (PDT) and photothermal therapy (PTT), respectively. So far, many photo-responsive agents have been developed. Among them, the metal-organic framework (MOF) is becoming one of the most promising photo-responsive materials because its structure and chemical compositions can be easily modulated to achieve specific functions. MOFs can have intrinsic photodynamic or photothermal ability under the rational design of MOF construction, or serve as the carrier of therapeutic agents, owing to its tunable porosity. MOFs also provide feasibility for various combined therapies and targeting methods, which improves the efficiency of phototherapy. In this review, we firstly investigated the principles of phototherapy, and comprehensively summarized recent advances of MOF in PDT, PTT and synergistic therapy, from construction to modification. We expect that our demonstration will shed light on the future development of this field, and bring it one step closer to clinical trials.

ALD-induced TiO2/Ag nanofilm for rapid surface photodynamic ion sterilization.

The daily life of people in the intelligent age is inseparable from electronic device, and a number of bacteria on touch screens are increasingly threatening the health of users. Herein, a photocatalytic TiO2/Ag thin film was synthesized on a glass by atomic layer deposition and subsequent in situ reduction. Ultraviolet-visible (UV-Vis) spectra showed that this film can harvest the simulated solar light more efficiently than that of pristine TiO2. The antibacterial tests in vitro showed that the antibacterial efficiency of the TiO2/Ag film against S. aureus and E. coli was 98.2% and 98.6%, under visible light irradiation for 5 min. The underlying mechanism was that the in-situ reduction of Ag on the surface of TiO2 reduced the bandgap of TiO2 from 3.44 to 2.61 eV due to the formation of Schottky heterojunction at the interface between TiO2 and Ag. Thus, TiO2/Ag can generate more reactive oxygen species for bacterial inactivation on the surface of electronic screens. More importantly, the TiO2/Ag film had great biocompatibility with/without light irradiation. The platform not only provides a more convenient choice for the traditional antibacterial mode but also has limitless possibilities for application in the field of billions of touch screens.

2D MOF Periodontitis Photodynamic Ion Therapy.

Traditional surgical intervention and antibiotic treatment are poor and even invalid for chronic diseases including periodontitis induced by diverse oral pathogens, which often causes progressive destruction of tissues, even tooth loss, and systemic diseases. Herein, an ointment comprising atomic-layer Fe2O3-modified two-dimensional porphyrinic metal-organic framework (2D MOF) nanosheets is designed by incorporating a polyethylene glycol matrix. After the atomic layer deposition surface engineering, the enhanced photocatalytic activity of the 2D MOF heterointerface results from lower adsorption energy and more charge transfer amounts due to the synergistic effect of metal-linker bridging units, abundant active sites, and an excellent light-harvesting network. This biocompatible and biodegradable 2D MOF-based heterostructure exhibits broad-spectrum antimicrobial activity (99.87 ± 0.09%, 99.57 ± 0.21%, and 99.03 ± 0.24%) against diverse oral pathogens (Porphyromonas gingivalis, Fusobacterium nucleatum, and Staphylococcus aureus) by the synergistic effect of reactive oxygen species and released ions. This photodynamic ion therapy exhibits a superior therapeutic effect to the reported clinical periodontitis treatment owing to rapid antibacterial activity, alleviative inflammation, and improved angiogenesis.

ZIF-67 derived Co@NC/g-C3N4 as a photocatalyst for enhanced water splitting H2 evolution.

Graphitic carbon nitride (g-C3N4), as the one of the most promising photocatalysts, usually relies on noble metal co-catalysts in the photocatalytic water splitting H2 evolution process, which greatly increases the use cost. Here, a zeolite imidazole framework (ZIF-67) derived Co@NC/g-C3N4 composite was constructed through facile thermal condensation of ZIF-67 and melamine. The obtained Co@NC/g-C3N4 composites can drive water splitting H2 evolution without any noble metal co-catalyst under simulated sunlight. The optimal sample exhibits the highest H2 evolution rate of 161 µmol g-1·h-1, which is 6 times of pure g-C3N4. The N doped carbon in carbonized ZIF-67 can not only quickly capture separated electrons from g-C3N4, but also serve as the co-catalyst. The well dispersed cobalt intermediate on carbonized ZIF-67 also play a role in promoting electron conversion. The formation of junction between carbonized ZIF-67 and g-C3N4 could promote quick charge carrier separation and transfer. This work provides a new idea for photocatalytic H2 evolution without noble metal co-catalysis.

Nitrogen-Doped Graphene-Encapsulated Nickel-Copper Alloy Nanoflower for Highly Efficient Electrochemical Hydrogen Evolution Reaction.

Development of high-performance and low-cost nonprecious metal electrocatalysts is critical for eco-friendly hydrogen production through electrolysis. Herein, a novel nanoflower-like electrocatalyst comprising few-layer nitrogen-doped graphene-encapsulated nickel-copper alloy directly on a porous nitrogen-doped graphic carbon framework (denoted as Nix Cuy @ NG-NC) is successfully synthesized using a facile and scalable method through calcinating the carbon, copper, and nickel hydroxy carbonate composite under inert atmosphere. The introduction of Cu can effectively modulate the morphologies and hydrogen evolution reaction (HER) performance. Moreover, the calcination temperature is an important factor to tune the thickness of graphene layers of the Nix Cuy @ NG-NC composites and the associated electrocatalytic performance. Due to the collective effects including unique porous flowered architecture and the synergetic effect between the bimetallic alloy core and graphene shell, the Ni3 Cu1 @ NG-NC electrocatalyst obtained under optimized conditions exhibits highly efficient and ultrastable activity toward HER in harsh environments, i.e., a low overpotential of 122 mV to achieve a current density of 10 mA cm-2 with a low Tafel slope of 84.2 mV dec-1 in alkaline media, and a low overpotential of 95 mV to achieve a current density of 10 mA cm-2 with a low Tafel slope of 77.1 mV dec-1 in acidic electrolyte.