Low‐cost transition‐metal chalcogenides (MSx) are demonstrated to be potential candidate cocatalyst for photocatalytic H2 generation. However, their H2‐generation performance is limited by insufficient quantities of exposed sulfur (S) sites and their strong bonding with adsorbed hydrogen atoms (SHads). To address these issues, an efficient coupling strategy of active‐site‐enriched regulation and electronic structure modification of active S sites is developed by rational design of core–shell Au@NiS1+x nanostructured cocatalyst. In this case, the Au@NiS1+x cocatalyst can be skillfully fabricated to synthesize the Au@NiS1+x modified TiO2 (denoted as TiO2/Au@NiS1+x) by a two‐step route. Photocatalytic experiments exhibit that the resulting TiO2/Au@NiS1+x(1.7:1.3) displays a boosted H2‐generation rate of 9616 µmol h−1 g−1 with an apparent quantum efficiency of 46.0% at 365 nm, which is 2.9 and 1.7 times the rate over TiO2/NiS1+x and TiO2/Au, respectively. In situ/ex situ XPS characterization and density functional theory calculations reveal that the free‐electrons of Au can transfer to sulfur‐enriched NiS1+x to induce the generation of electron‐enriched Sδ− active centers, which boosts the desorption of Hads for rapid hydrogen formation via weakening the strong SHads bonds. Hence, an electron‐enriched Sδ−‐mediated mechanism is proposed. This work delivers a universal strategy for simultaneously increasing the active site number and optimizing the binding strength between the active sites and hydrogen adsorbates.
Along
with the rapid appearance of superbacteria with multidrug
resistance, it is a challenge to develop new antibacterial materials
to address this big issue. Herein, we report a novel amine group-modified
fullerene derivative (C70–(ethylenediamine)8 abrr. C70–(EDA)8), which reveals
a high performance in killing superbacteria, and most importantly,
it shows negligible toxicity to the mammalian cells. The strong antibacterial
ability of this material was attributed to its unique molecular structure.
On one hand, amino groups on the EDA part make it easy to affix onto
the outer membrane of multidrug resistance Escherichia
coli by electrostatic interactions. On the other hand,
the hydrophobic surface on the C70 part makes it easy to
form a strong hydrophobic interaction with the inner membrane of bacteria.
Finally, C70–(EDA)8 leads to the cytoplast
leakage of superbacteria. In contrast, the C70–(EDA)8 is nontoxic for mammalian cells due to different distributions
of the negative charges in the cell membrane. In vivo studies indicated
that C70–(EDA)8 mitigated bacterial infection
and accelerated wound healing by regulating the immune response and
secretion of growth factors. Our amine group-based fullerene derivatives
are promising for clinical treatment of wound infection and offer
a new way to fight against the superbacteria.
Developing efficient, stable, and low-cost novel electron-cocatalysts is crucial for photocatalytic hydrogen evolution reaction. Herein, amorphous NiP alloy particles were successfully modified onto g-C 3 N 4 to construct the Ni-P/ g-C 3 N 4 photocatalyst through a simple and green triethanolamine (TEOA)-mediated photodeposition method. It was found that the TEOA could serve as an excellent complexing agent to coordinate with Ni 2+ to form [Ni(TEOA)] 2+ complex, which can promote the rapid and effective deposition of amorphous NiP alloy on the g-C 3 N 4 surface. Photocatalytic tests suggest that the hydrogen-evolution performance of g-C 3 N 4 can be greatly promoted through integrating amorphous NiP alloy. Especially, the Ni-P/g-C 3 N 4 (5 wt%) exhibits the superior H 2-generation activity (118.2 μmol h −1 g −1), which is almost 35.8 times that of bare g-C 3 N 4. Furthermore, the amorphous NiP alloy cocatalyst can also serve as the general hydrogen-production cocatalyst to greatly enhance the photocatalytic performance of traditional semiconductor materials such as TiO 2 and CdS. Based on the present results, the mechanism of the amorphous NiP alloy as the high-efficiency electron transfer medium was proposed for the boosted H 2generation rate. The present facile route may broaden the horizons for the efficient development of highly active cocatalysts in photocatalytic field.
Rhenium disulfide (ReS2) holds expansive perspective in photocatalytic water‐splitting field, but its H2‐production rate is severely impeded by the strong hydroxyl (OHad) adsorption on catalytic Re atoms. Herein, an ingenious strategy about charging d‐orbital electrons of ReS2+x cocatalyst by integrating metallic Au is explicitly clarified to effectively accelerate OHad desorption for promoting alkaline photocatalytic H2‐evolution activity. To this end, core‐shell Au@ReS2+x nanostructures as H2‐production cocatalysts are skillfully fabricated onto TiO2 by a directional assembly pathway. Experimental and theoretical data validate an free‐electron transfer from metallic Au core to S‐rich ReS2+x shell, thus essentially charging electrons to the d‐orbital of Re atoms to construct active Re(4‐δ)+ sites. The charged d‐orbital electron state of Re(4‐δ)+ atoms raises antibonding occupancy of the Re(4‐δ)+OHad bonds, thereby accelerating OHad desorption and endowing core‐shell Au@ReS2+x cocatalysts an efficient H2 production from alkaline water splitting. Moreover, the core‐shell Au@ReS2+x cocatalysts can effectively capture photogenerated electrons from TiO2 as unveiled by operando Kelvin probe force microscopy. Consequently, the optimized TiO2/Au@ReS2+x photocatalyst achieves an exceptional H2‐production rate of 6013.45 µmol h−1 g−1 with releasing visual H2 bubbles in alkaline media. This research furnishes original insights for charging orbital electrons to optimize the adsorption strength between intermediates and catalytic atoms.
Exploiting highly efficient, noble metal-free, and ultra-small H2-evolution cocatalysts is crucial to promoting photocatalytic water splitting reaction. Herein, the ultra-small non-crystalline CuxP nanodots (CuxP-ND) as an efficient H2-evolution cocatalyst were...
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