Improving charge transport and reducing bulk/surface recombination can increase the activity and stability of BiVO4 for water oxidation. Herein we demonstrate that the photoelectrochemical (PEC) ...performance of BiVO4 can be significantly improved by potentiostatic photopolarization. The resulting cocatalyst‐free BiVO4 photoanode exhibited a record‐high photocurrent of 4.60 mA cm−2 at 1.23 VRHE with an outstanding onset potential of 0.23 VRHE in borate buffer without a sacrificial agent under AM 1.5G illumination. The most striking characteristic was a strong “self‐healing” property of the photoanode, with photostability observed over 100 h under intermittent testing. The synergistic effects of the generated oxygen vacancies and the passivated surface states at the semiconductor–electrolyte interface as a result of potentiostatic photopolarization reduced the substantial carrier recombination and enhanced the water oxidation kinetics, further inhibiting photocorrosion.
Potentiostatic photopolarization was induced on BiVO4 to improve charge transport, reduce interface recombination, and improve the water oxidation kinetics. The undoped BiVO4 photoanode exhibited a record‐high photocurrent of 4.60 mA cm−2 at 1.23 VRHE with an onset potential of 0.23 VRHE in borate buffer without a cocatalyst or a sacrificial agent. Strong “self‐healing” characteristics enabled photostability over 100 h under intermittent testing (see picture).
Increasing long‐term photostability of BiVO4 photoelectrode is an important issue for solar water splitting. The NiOOH oxygen evolution catalyst (OEC) has fast water oxidation kinetics compared to ...the FeOOH OEC. However, it generally shows a lower photoresponse and poor stability because of the more substantial interface recombination at the NiOOH/BiVO4 junction. Herein, we utilize a plasma etching approach to reduce both interface/surface recombination at NiOOH/BiVO4 and NiOOH/electrolyte junctions. Further, adding Fe2+ into the borate buffer electrolyte alleviates the active but unstable character of etched‐NiOOH/BiVO4, leading to an outstanding oxygen evolution over 200 h. The improved charge transfer and photostability can be attributed to the active defects and a mixture of NiOOH/NiO/Ni in OEC induced by plasma etching. Metallic Ni acts as the ion source for the in situ generation of the NiFe OEC over long‐term durability.
Flex your PECs: A facile plasma etching approach was utilized to reduce both interface/surface recombination at NiOOH/BiVO4 and NiOOH/electrolyte junctions for photoelectrochemical (PEC) catalysis of water splitting. Addition of Fe2+ into the borate buffer electrolyte alleviated the active but unstable character of etched‐NiOOH/BiVO4, leading to an outstanding photostability over 200 h.
A photocharge/discharge strategy is proposed to initiate the WO3 photoelectrode and suppress the main charge recombination, which remarkably improves the photoelectrochemical (PEC) performance. The ...photocharged WO3 surrounded by a 8–10 nm overlayer and oxygen vacancies could be operated more than 25 cycles with 50 h durability without significant decay on PEC activity. A photocharged WO3/CuO photoanode exhibits an outstanding photocurrent of 3.2 mA cm−2 at 1.23 VRHE with a low onset potential of 0.6 VRHE, which is one of the best performances of p‐n heterojunction structure. Using nonadiabatic molecular dynamics combined with time‐domain DFT, we clarify the prolonged charge carrier lifetime of photocharged WO3, as well as how electronic systems of photocharged WO3/CuO semiconductors enable the effective photoinduced electrons transfer from WO3 into CuO. This work provides a feasible route to address excessive defects existed in photoelectrodes without causing extra recombination.
A photocharging/discharging strategy is used to initiate the WO3 electrode and prolong charge carrier lifetime for the oxygen evolution reaction. A WO3/CuO photoanode exhibited an outstanding photocurrent with a low onset potential. The prolonged charge carrier lifetime of photocharged WO3 and the electronic systems of photocharged WO3/CuO semiconductors were clarified using the nonadiabatic molecular dynamics combined with time‐domain DFT.
Photostability is one of the most essential properties for evaluating photoelectrochemical (PEC) water splitting performance on semiconductors. Herein, the oxygen‐deficiency conditions are applied to ...tune and activate BiVO4 photoanodes with a class of oxygen vacancies across the whole bulk material, and regulate the electronic occupancy of these states upon the charge carrier processes that determine PEC water oxidation activity. Through the experimental results and nonadiabatic molecular dynamics with time‐domain density functional theory calculations, the charge carrier lifetime can be influenced by the oxygen vacancies concentration on BiVO4, and the semiconductor can be flexibly photoactivated under oxygen‐sufficient and deficient atmospheres for enhancing the charge carrier density and photovoltage. The PEC performance of BiVO4 is further boosted by Pt doping, which exhibits a record photocurrent density of 5.45 mA cm–2 at 1.23 VRHE with solar conversion efficiency of 2.1% at 0.65 VRHE. The Pt can prevent the unnecessory charge recombination on the defected BiVO4, which also enhances the majority charge carrier density, resulting in one of the best charge separation efficiencies, close to 100%, among the steady‐state PEC performance for BiVO4. More importantly, the resulting Pt:BiVO4 presents long‐term stability over 50 h at 0.8 VRHE.
Herein, oxygen‐deficiency conditions are applied to tune and activate BiVO4 photoanodes with a class of oxygen vacancies across the whole bulk material, and regulate the electronic occupancy of these states upon the charge carrier processes that determine photoelectrochemical (PEC) water oxidation activity. The material is doped with Pt, which further enhances the majority charge carrier density, resulting in one of the best charge separation efficiencies, close to 100%, among the steady‐state PEC performance for BiVO4 photoanodes.
Recently, the dysregulation of circular RNA (circRNA) have been shown to have important regulatory roles in cancer development and progression, including hepatocellular carcinoma (HCC). However, the ...roles of most circRNAs in HCC are still unknown.
The expression of circular tripartite motif containing 33-12 (circTRIM33-12) in HCC tissues and cell lines was detected by qRT-PCR. The role of circTRIM33-12 in HCC progression was assessed by western blotting, CCK-8, flow cytometry, transwell and a subcutaneous tumor mouse assays both in vitro and in vivo. In vivo circRNA precipitation, RNA immunoprecipitation, luciferase reporter assays were performed to evaluate the interaction between circTRIM33-12 and miR-191.
Here, we found that circTRIM33-12, is downregulated in HCC tissues and cell lines. The downregulation of circTRIM33-12 in HCC was significantly correlated with malignant characteristics and served as an independent risk factor for the overall survival (OS) and recurrence-free survival (RFS) of patients with HCC after surgery. The reduced expression of circTRIM33-12 in HCC cells increases tumor proliferation, migration, invasion and immune evasion. Mechanistically, we demonstrated that circTRIM33-12 upregulated TET1 expression by sponging miR-191, resulting in significantly reduced 5-hydroxymethylcytosine (5hmC) levels in HCC cells.
These results reveal the important role of circTRIM33-12 in the proliferation, migration, invasion and immune evasion abilities of HCC cells and provide a new perspective on circRNAs in HCC progression.
Ammonia (NH3) is recognized as a transportable carrier for renewable energy fuels. Photoelectrochemical nitrate reduction reaction (PEC NO3RR) offers a sustainable solution for nitrate‐rich ...wastewater treatment by directly converting solar energy to ammonia. In this study, we demonstrate the highly selective PEC ammonia production from NO3RR by constructing a CoCu/TiO2/Sb2Se3 photocathode. The constructed CoCu/TiO2/Sb2Se3 photocathode achieves an ammonia Faraday efficiency (FE) of 88.01 % at −0.2 VRHE and an ammonia yield as high as 15.91 μmol h−1 cm−2 at −0.3 VRHE with an excellent onset potential of 0.43 VRHE. Dynamics experiments and theoretical calculations have demonstrated that the CoCu/TiO2/Sb2Se3 photocathode possesses high light absorption capacity, excellent carrier transfer capability, and high charge separation and transfer efficiencies. The photocathode can effectively adsorb the reactant NO3− and intermediate, and the CoCu co‐catalyst increases the maximum Gibbs free energy difference between NO3RR and HER. Meanwhile, the Co species enhances the spin density of Cu, and increases the density of states near the Fermi level in pdos, which results in a high PEC NO3RR activity on CoCu/TiO2/Sb2Se3. This work provides a new avenue for the feasibility of efficient PEC ammonia synthesis from nitrate‐rich wastewater.
The highly selective photoelectrochemical ammonia production from NO3 reduction reaction can be achieved by constructing a CoCu/TiO2/Sb2Se3 photocathode. The photocathode achieves an ammonia Faraday efficiency of 88.01 % and an ammonia yield as high as 15.91 μmol h−1 cm−2 with an excellent onset potential of 0.43 VRHE. It provides a new avenue for the feasibility of efficient PEC ammonia synthesis from nitrate‐rich wastewater.
Neutral electrolysis to produce hydrogen is prime challenging owing to the sluggish kinetics of water dissociation for the electrochemical reduction of water to molecular hydrogen. An ion‐enriched ...electrode/electrolyte interface for electrocatalytic reactions can efficiently obtain a stable electrolysis system. Herein, we found that interfacial accumulated fluoride ions and the anchored Pt single atoms/nanoparticles in catalysts can improve hydrogen evolution reaction (HER) activity of NiFe‐based hydroxide catalysts, prolonging the operating stability at high current density in neutral conditions. NiFe hydroxide electrode obtains an outstanding performance of 1000 mA cm−2 at low overpotential of 218 mV with 1000 h operation at 100 mA cm−2. Electrochemical experiments and theoretical calculations have demonstrated that the interfacial fluoride contributes to promote the adsorption of Pt to proton for sustaining a large current density at low potential, while the Pt single atoms/nanoparticles provide H adsorption sites. The synergy effect of F and Pt species promotes the formation of Pt─H and F─H bonds, which accelerate the adsorption and dissociation process of H2O and promote the HER reaction with a long‐term durability in neutral conditions.
The interfacial accumulated fluoride ions and the anchored Pt single atoms/nanoparticles improve hydrogen evolution reaction activity and stability of NiFe‐based hydroxide catalysts in neutral conditions.
Although much effort has been devoted to improving photoelectrochemical water splitting of hematite (α-Fe
O
) due to its high theoretical solar-to-hydrogen conversion efficiency of 15.5%, the low ...applied bias photon-to-current efficiency remains a huge challenge for practical applications. Herein, we introduce single platinum atom sites coordination with oxygen atom (Pt-O/Pt-O-Fe) sites into single crystalline α-Fe
O
nanoflakes photoanodes (SAs Pt:Fe
O
-Ov). The single-atom Pt doping of α-Fe
O
can induce few electron trapping sites, enhance carrier separation capability, and boost charge transfer lifetime in the bulk structure as well as improve charge carrier injection efficiency at the semiconductor/electrolyte interface. Further introduction of surface oxygen vacancies can suppress charge carrier recombination and promote surface reaction kinetics, especially at low potential. Accordingly, the optimum SAs Pt:Fe
O
-Ov photoanode exhibits the photoelectrochemical performance of 3.65 and 5.30 mA cm
at 1.23 and 1.5 V
, respectively, with an applied bias photon-to-current efficiency of 0.68% for the hematite-based photoanodes. This study opens an avenue for designing highly efficient atomic-level engineering on single crystalline semiconductors for feasible photoelectrochemical applications.
The chloride ions in seawater result in corrosion, low catalytic efficiency, and poor stability of the electrocatalysts in direct seawater electrolysis, which limits the use of large‐scale seawater ...electrolysis technology. Herein, a corrosion‐resistant Ag/NiFeRu layered double hydroxide (LDH) electrocatalyst for seawater electrolysis at industrial current density, in which Ru and Ag species in the catalyst can have a corrosion‐resistance of chloride ions from the anode surface and enhance its robustness in seawater is designed. The catalyst requires the overpotentials of 256 and 287 mV to obtain a current density of 1 A cm−2 in 1 m KOH and 1 m KOH + seawater, respectively. More importantly, it works stably for over 1000 h at 1 A cm−2 in alkaline seawater. Further quasi‐industrial conditions measurement (6 m KOH + seawater, 60 °C) shows a markedly low overpotential of 174 mV at 1 A cm−2 on Ag/NiFeRu LDH, obtaining over 140 h under harsh industrial conditions. Theoretical calculations demonstrate that the Ru species can effectively regulate the local electronic structure of NiFe LDH, and enhance the intrinsic activity of NiFe LDH. The transformation of Ag2O from Ag during OER stabilizes the Fe site in NiFe LDH, which improves the overall stability of the electrocatalyst.
Ru and Ag synergetic regulation NiFe LDH exhibits excellent activity and stability in industrial seawater electrolysis. This catalyst requires a low overpotential of 287 mV to obtain a current density of 1 A cm−2 in 1 m KOH + seawater with a long‐term operation of 1000 h.
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