Engineering Surface Passivation and Hole Transport Layer on Hematite Photoanodes Enabling Robust Photoelectrocatalytic Water Oxidation

Regulation of charge transport at the molecular level is essential to elucidating the kinetics of junction photoelectrodes across the heterointerface for photoelectrochemical (PEC) water oxidation. Herein, an integrated photoanode as the prototype was constructed by use of a 5,10,15,20-tetrakis(4-carboxyphenyl) porphyrin-cobalt molecule (CoTCPP) and ZnO on hematite (α-Fe2O3) photoanode. CoTCPP molecules serve as a typical hole transport layer (HTL), accelerating the transport of the photogenerated holes to oxygen evolution cocatalysts (OECs). Meanwhile, ZnO as the surface passivation layer (SPL) can passivate the interfacial state and reduce the level of electron leakage from hematite into the electrolyte. After the integration of OECs, the state-of-the-art α-Fe2O3/ZnO/CoTCPP/OECs photoanode exhibits a distinguished photocurrent density and excellent stability in comparison with pristine α-Fe2O3. The simultaneous incorporation of a ZnO and CoTCPP dual interlayer can effectively modulate the interfacial photoinduced charge transfer for PEC reaction. This work provides in-depth insights into interfacial charge transfer across junction electrodes and identifies the critical roles of solar PEC conversion

BiVO₄‑Based Heterojunction Photocathode for High-Performance Photoelectrochemical Hydrogen Peroxide Production

Photoelectrochemical (PEC) cells provide a promising solution for the synthesis of hydrogen peroxide (H2O2). Herein, an integrated photocathode of p-type BiVO4 (p-BVO) array with tetragonal zircon structure coupled with different metal oxide (MOx, M = Sn, Ti, Ni, and Zn) heterostructure and NiNC cocatalyst (p-BVO/MOx/NiNC) was synthesized for the PEC oxygen reduction reaction (ORR) in production of H2O2. The p-BVO/SnO2/NiNC array achieves the production rate 65.46 μmol L–1 h–1 of H2O2 with a Faraday efficiency (FE) of 76.12%. Combined with the H2O2 generation of water oxidation from the n-type Mo-doped BiVO4 (n-Mo:BVO) photoanode, the unbiased photoelectrochemical cell composed of a p-BVO/SnO2/NiNC photocathode and n-Mo:BVO photoanode achieves a total FE of 97.67% for H2O2 generation. The large area BiVO4-based tandem cell of 3 × 3 cm2 can reach a total H2O2 production yield of 338.84 μmol L–1. This work paves the way for the rational design and fabrication of artificial photosynthetic cells for the production of liquid solar fuel

The effect of CMG2-Fc (E117Q) on the survival of F344 rats challenged with lethal toxin (LeTx).

<p>The weight ratio of CMG2-Fc to lethal factor was evaluated at 1∶1. The rest may be deduced by analogy.</p

The primers for engineering the mutated constructs.

<p>The primers for engineering the mutated constructs.</p

Structure of the CMG2-PA complex.

<p>(A) The crystal structure of the CMG2-PA complex (PDB ID: 1T6B). PA is shown in red, CMG2 is shown in green, and the interface residues on CMG2 are shown in blue. (B) Close views of the interactions between PA D683 and CMG2 E117. The two residues are shown as sticks and balls. PA D683 is depicted in yellow, and CMG2 E117 is depicted in blue. (C) Close views of the interactions between PA 344R and CMG2 Y158. The two residues are shown as sticks and balls. PA R344 is depicted in magenta, and CMG2 Y158 is depicted in blue.</p

Zircon U–Pb geochronology and geochemistry of the post-collisional volcanic rocks in eastern Xinjiang Province, NW China: implications for the tectonic evolution of the Junggar terrane

<p>We report zircon U–Pb geochronologic and geochemical data for the post-collisional volcanic rocks from the Batamayineishan (BS) Formation in the Shuangjingzi area, northwestern China. The zircon U–Pb ages of seven volcanic samples from the BS Formation show that the magmatic activity in the study area occurred during 342–304 Ma in the Carboniferous. The ages also indicate that the Palaeo-Karamaili Ocean had already closed by 342 Ma. Moreover, the volcanic rocks also contained 10 inherited zircons with ages ranging from 565 to 2626 Ma, indicating that Precambrian continental crust or microcontinents with accretionary arcs are two possible interpretations for the basement underlying the East Junggar terrane. The sampled mafic-intermediate rocks belong to the medium-K to high-K calc-alkaline and shoshonitic series, and the formation of these rocks involved fractional crystallization with little crustal contamination. These Carboniferous mafic-intermediate rocks show depletions in Nb and Ta and enrichments in large ion lithophile elements (e.g. Rb, Ba, U, and Th) and light rare earth elements. The low initial ⁸⁷Sr/⁸⁶Sr values (0.7034–0.7042) and positive <i>ε</i>_Nd(<i>t</i>) values (+2.63 to +6.46) of these rocks suggest that they formed from depleted mantle material. The mafic-intermediate rocks were most likely generated by 5–10% partial melting of a mantle source composed primarily of spinel lherzolite with minor garnet lherzolite that had been metasomatized by slab-derived fluids and minor slab melts. In contrast, the felsic rocks in the BS Formation are A-type rhyolites with positive <i>ε</i>_Nd(<i>t</i>) values and young model ages. These rocks are interpreted to be derived from the partial melting of juvenile basaltic lower crustal material. Taken together, the mafic-intermediate rocks formed in a post-collisional extensional setting generated by slap breakoff in the early Carboniferous (342–330 Ma) and the A-type rhyolites formed in a post-collisional extensional setting triggered by the upwelling asthenosphere in the late Carboniferous (330–304 Ma).</p

The predicted differences in binding energies (ΔΔ<i>G</i>) of CMG2 variants binding to PA compared to wild-type CMG2.

<p>Note: The change in energy is measured in kcal/mol and applies to the change of a single binding interface bound to a PA molecule.</p

Geochemistry and geochronology of Upper Permian–Upper Triassic volcanic rocks in eastern Jilin Province, NE China: implications for the tectonic evolution of the Palaeo-Asian Ocean

<p>We present zircon U–Pb dating, whole-rock geochemistry, and Sr–Nd isotope results for the Upper Permian–Upper Triassic volcanic rocks to constrain the timing of the final closure of the eastern segment of the Palaeo-Asian Ocean. The volcanic rocks were mainly collected from the Yanbian area in eastern Jilin Province, northeastern China. The zircon U–Pb dating results indicate that the samples can be classified as Upper Permian–Lower Triassic basalts (ca. 262–244 Ma) and Upper Triassic dacites (ca. 216 Ma). The whole-rock geochemical results indicate that the rocks predominately belong to the medium-K and high-K calc-alkaline series. The basalts are enriched in large ion lithophile elements (LILEs, e.g. Ba and K) and depleted in high field strength elements (HFSEs, e.g. Nb and Ta), with weak positive Eu anomalies. The dacites are enriched in LILEs (e.g. Rb, Ba, Th, and K) and light rare earth elements (LREEs) and marked depletion in some HFSEs (e.g. Nb, Ta, and Ti), with significant negative Sr, P, and Eu anomalies. Moreover, the Upper Permian–Lower Triassic basalts have low initial ⁸⁷Sr/⁸⁶Sr ratios (0.7037–0.7048) and high <i>ε</i>_Nd values (4.4–5.4). In contrast, the Upper Triassic dacites possess relatively high initial ⁸⁷Sr/⁸⁶Sr ratios (0.7052) compared with their low <i>ε</i>_Nd values (1.4). The basaltic magma likely originated from the partial melting of a depleted mantle wedge metasomatized by subduction-related fluids, and the felsic magmas likely originated from the partial melting of a dominantly juvenile source with a minor component of ancient crust. Taken together, the Upper Permian–Lower Triassic basalts (ca. 262–244 Ma) are arc basalts that formed in an active continental margin setting, and the Upper Triassic dacites (ca. 216 Ma) are A-type granitic rocks that formed in an extensional setting. Therefore, the final closure of the Palaeo-Asian Ocean occurred during the Middle–Late Triassic.</p

Predicted structures for designed mutations; green ribbon, PA backbone; magenta ribbon, CMG2 backbone.

<p>Carbon atom, cyan; Nitrogen atom, blue; Oxygen atom, red. Mutation of CMG2 117 Glu to Gln is shown in (A) and (B), residues 117, 52, 54 and PA 683 are highlighted as sticks and balls. (C) and (D) indicate CMG2 158Tyr to Gln, position 158 of CMG2 and residues 342–344 of PA are highlighted as sticks and balls. Binding energies are given beneath.</p

Toxin neutralization assay analyzing the CMG2-Fc mutants.

<p>The experiments were performed at different concentrations and dilutions due to the different abilities of the different mutants to neutralize LeTx. The data points represent the mean ± SD values of triplicate samples.</p