Ce Hao

In this paper, we investigated the role of excited-state hydrogen bonding in the photocatalytic carbon dioxide reduction reaction (CO₂RR) utilizing Rose Bengal as a catalyst, through a combined experimental and theoretical approach.

In this paper, we report a joint experimental and computational study to elaborate the mechanism for the photocatalytic CO₂ reduction reaction (CO₂RR).

Citalopram (CIT) is a commonly prescribed medication for depression. However, the photodegradation mechanism of CIT has not yet been fully analyzed. Therefore, the photodegradation process of CIT in water is studied by density functional theory and time-dependent density functional theory. The calculated results show that during the indirect photodegradation process, the indirect photodegradation of CIT with ·OH occurs via OH-addition and F-substitution. The minimum activation energy of C10 site was 0.4 kcal/mol. All OH-addition and F-substitution reactions are exothermic. The reaction of ¹O₂ with CIT includes the substitution of ¹O₂ for F and an addition reaction at the C14 site. The E_a value of this process is 1.7 kcal/mol, which is the lowest activation energy required for the reaction of ¹O₂ with CIT. C–C/C–N/C–F cleavage is involved in the direct photodegradation process. In the direct photodegradation of CIT, the activation energy of the C7-C16 cleavage reaction was the lowest, which was 12.5 kcal/mol. Analysis of the E_a values found that OH-addition and F-substitution, the substitution of ¹O₂ for F and addition at the C14 site, as well as the cleavage reactions of C6–F/C7–C16/C17–C18/C18–N/C19–N/C20–N are the main pathways of photodegradation of CIT.

Controllable development of cost-effective oxygen reduction reaction (ORR) catalysts with a bottom-up method is one of the primary remaining challenges in catalysis due to the complexity and random reaction among ingredient molecules. Herein, a B and N co-doped metal-free carbonaceous (BNC) catalyst with hierarchical porous structure and super high specific surface area was rationally constructed by a secondary pyrolysis method for the ORR. By comparatively analyzing the preparation parameter–structure relationship, the addition time of the B precursor was proved to have a key influence on the B doping content. Meanwhile, the secondary pyrolysis procedure endowed BNC with a large amount of homogeneous exposed N and B active species, abundant mass transfer nanopores, and high conductivity. Consequently, BNC provides an outstanding ORR activity with an onset potential of 0.94 V and a half-wave potential of 0.84 V, which are similar to those of Pt/C. More importantly, a BNC based Zn–air battery delivers high peak power density (115.5 mW cm⁻²) and good discharge stability (45 h).

Nanoscale pyrazolate-based coordination polymers (CPs) are becoming increasingly popular as electrocatalysts owing to their customizable compositions and structures. However, using them for oxygen evolution reaction (OER) is highly challenging due to their unsatisfactory catalytic efficiency and relatively low stability. Herein, a simple one-step solvothermal process was employed for the fabrication of polycrystalline nickel-pyrazolate [Ni(Pz)] with an unusual lamellar nanorod-assembled microsphere morphology for the first time using ethanol as a green organic solvent via controlling other physical parameters. Meanwhile, the Ni(Pz) structure and morphology are investigated to derive its formation process following the different monomeric feed ratios relying on the metal/ligand interactions of CP. Shaping the Ni(Pz) electrocatalyst in well-oriented lamellar nanorod-assembled microspheres brings the advantage of porosity and high specific surface area, which expedites mass/charge transport and contact with the electrolyte as well as creates less tortuous pathways for charge distribution, thus improving the charge homogeneity. These high-class structural features and polycrystalline nature of Ni(Pz)-E-PVP facilitate amazing catalytic OER activity with a low overpotential of 290 mV at 10 mA cm(-2) and a Tafel slope of only 94 mV dec(-1) beyond the yardstick material (i.e., RuO2) in alkaline solution. A suite of measurements, entailing X-ray photoelectron spectroscopy and density functional theory calculations, suggest that the rich Ni-N-4 moieties in Ni(Pz)-E-PVP are central species providing adsorption sites for OER intermediates. This facile protocol is prophesied to commence the imminent development of noble metal-free, effective, and low-priced electrocatalysts for OER.

Glycolaldehyde, a C2 compound, is the simplest sugar molecule, but whether it inherently exists in plants remains unclear due to its complicated existence form in different reaction conditions. By combination of a one-step chemical derivation method and high-performance liquid chromatography-mass spectrometry (HPLC-MS) measurements, herein, we clarify that the glycolaldehyde monomer molecule exists in aqueous media. Consequently, we report, for the first time, the identification of glycolaldehyde in various green plants such as Chlorella, spinach, maize, and Aeonium decorum f. variegate of the genus Aeonium. The present study provides direct evidence for the determination of glycolaldehyde and enriches our understanding of the chemical processes of biological metabolism in the plant kingdom.

In order to overcome the shuttling effect of soluble polysulfides in lithium–sulfur (Li–S) batteries, we have designed and synthesized a creative MoS₂–MoO₃/carbon shell (MoS₂–MoO₃/CS) composite by a H₂O₂-enabled oxidizing process under mild conditions, which is further used for separator modification. The MoS₂–MoO₃ heterostructures can conform to the CS morphology, forming two-dimensional nanosheets, and thus shorten the transport path of lithium ion and electrons. Based on our theoretical calculations and experiments, the heterostructures show strong surface affinity toward polysulfides and good catalytic activity to accelerate polysulfide conversion. Benefiting from the above merits, the Li–S battery with a MoS₂–MoO₃/CS modified separator exhibits good electrochemical performance: it delivers a high discharge capacity of 1531 mAh g^–1 at 0.2 C; the initial capacity can be maintained by 92% after 600 cycles at 1 C, and the discharge capacity decay rate is only 0.0135% per cycle. Moreover, the MoS₂–MoO₃/CS battery still achieves good cycling stability with 78% capacity retention after 100 cycles at 0.2 C with a high sulfur loading of 5.9 mg cm^–2. This work offers a facile design to construct the MoS₂–MoO₃ heterostructures for high-performance Li–S batteries, and may also improve one’s understanding on the heterostructure contribution during polysulfide adsorption and conversion.

A N, S co-doped porous carbon thin film was coated in situ on CNT via a simple and scalable polymerization-pyrolysis strategy, which exhibits extraordinary ORR/OER performance in half-cell tests and Zn–air batteries.