Schottky Junctions with Bi@Bi2MoO6 Core-Shell Photocatalysts toward High-Efficiency Solar N2-to-Ammonnia Conversion in Aqueous Phase

The photocatalytic nitrogen reduction reaction (NRR) in aqueous solution is a green and sustainable strategy for ammonia production. Nonetheless, the efficiency of the process still has a wide gap compared to that of the Haber-Bosch one due to the difficulty of N2 activation and the quick recombination of photo-generated carriers. Herein, a core-shell Bi@Bi2MoO6 microsphere through constructing Schottky junctions has been explored as a robust photocatalyst toward N2 reduction to NH3. Metal Bi self-reduced onto Bi2MoO6 not only spurs the photo-generated electron and hole separation owing to the Schottky junction at the interface of Bi and Bi2MoO6 but also promotes N2 adsorption and activation at Bi active sites synchronously. As a result, the yield of the photocatalytic N2-to-ammonia conversion reaches up to 173.40 μmol g-1 on core-shell Bi@Bi2MoO6 photocatalysts, as much as two times of that of bare Bi2MoO6. This work provides a new design for the decarbonization of the nitrogen reduction reaction by the utilization of renewable energy sources.

Bi/BiVO4/NiFe-LDH heterostructures with enhanced photoelectrochemical performance for streptomycin detection

Streptomycin (STR) plays an essential role in bacterial infection treatments. Selectivity and sensitivity of photoelectrochemical (PEC) sensors are the two most important parameters, which can be measured using the photosensitivity of its active material. We prepared a novel PEC sensor to detect STR using Bi/BiVO₄/LDH (layered double hydroxides) heterostructures as an active material, which is photoactive in the visible light wavelength range. The simultaneous presence of LDH and Bi/BiVO₄ enhanced the material photocurrent response, which was linear to the STR concentrations in the 0.01-500 nmol/L range. The STR detection limit by this sensor was 0.0042 nmol/L. Our novel PEC-based sensing strategy includes using an ultra-sensitive and highly selective sensor for STR detection. Additionally, the two-pot synthesis of Bi/BiVO₄/LDH developed in this work is environmentally friendly.

Highly Selective Production of Ethanol Over Hierarchical Bi@Bi2 MoO6 Composite via Bicarbonate-Assisted Photocatalytic CO2 Reduction

Photocatalytic CO₂ reduction is a sustainable and inexpensive method to solve the energy crisis and the greenhouse effect. However, the major stumbling blocks such as poor product selectivity, low yield of the multi-carbon products, and serious recombination of electron-hole pairs hinder practical application of photocatalysts. Herein, a high-performance Bi@Bi₂ MoO₆ photocatalyst, Bi nanoparticles grown on the surface of Bi₂ MoO₆ nanosheets with oxygen vacancies, was fabricated via a simple solvothermal approach. Benefiting from the abundant active sites and effective separation of photogenerated carriers of Bi₂ MoO₆ nanosheets, and the localized surface plasmon resonance effect of Bi nanoparticles, the Bi@Bi₂ MoO₆ sample exhibited great photocatalytic CO₂ reduction activity. Furthermore, adding NaHCO₃ into the system not only significantly increased the C₂ H₅ OH generation rate but also enhanced the product selectivity. In the photocatalytic measurement (0.17 mol L^-1 CO₂ -saturated NaHCO₃ solution), the highest formation rates of CO, CH₃ OH, and C₂ H₅ OH were reached at 0.85, 0.59, and 17.93 μmol g^-1  h^-1 (≈92 % selectivity), respectively.

Highly Intensified Molecular Oxygen Activation on Bi@Bi2MoO6 via a Metallic Bi-Coordinated Facet-Dependent Effect

Construction of the semimetal/semiconductor composite interface is widely used to promote the O₂ molecule adsorption and charge transfer for boosting solar-driven molecular oxygen activation (MOA). Herein, a Bi@Bi₂MoO₆ heterostructure is fabricated via a two-step wet chemical method as a typical photocatalyst to investigate the underlying mechanism of Bi-coordinated facet-dependent MOA under visible-light illumination. Density functional theory and systematical characterization methods reveal the distinct charge transfer and O₂ activation processes on the surface of Bi nanoparticle-deposited Bi₂MoO₆ nanosheets with different facets exposed. By virtue of a particular and efficient [Bi₂O₂]²⁺ → Bi → MoO₄^2- interfacial charge-transfer channel, Bi deposited on the (001) facet of Bi₂MoO₆ can observably intensify MOA, thereby giving birth to more generation of reactive oxygen species and endowing the Bi@Bi₂MoO₆ with excellent photocatalytic performance in sodium pentachlorophenate (NaPCP) removal. The decomposition pathway of NaPCP is also proposed based on the intermediate determination and mineralization analysis. This work provides deep insights into the mechanism of facet-dependent MOA over a semimetal-semiconductor system and also sheds light on designing effective molecular oxygen-activated interface for environmental remediation.

Hierarchical nanosheet-based Bi2MoO6 microboxes for efficient photocatalytic performance

Hierarchical nanosheet-based Bi₂MoO₆ microboxes are synthesized by a facile template-assisted strategy.

A novel theranostic agent based on porous bismuth nanosphere for CT imaging-guided combined chemo-photothermal therapy and radiotherapy

A novel theranostic agent based on porous bismuth (pBi) nanospheres was developed for tumor imaging and combined chemotherapy, photothermal therapy and radiotherapy.

Fabrication and behaviors of CdS on Bi2MoO6 thin film photoanodes

Most Bi-based photoelectrodes have suitable band gaps and can effectively promote hydrogen evolution from water splitting, but there are few studies up to now for simple preparation methods for Bi-based binary metal oxides as photoanodes.