US 12110434 B1Patent grantUnited States

Room-Temperature Bismuth Oxyhalide Quantum Dots

Official patent title

Bismuth oxyhalide-based quantum dots and method of synthesis thereof

Arabic title: نقاط كمومية قائمة على أوكسي هاليد البزموت وطريقة تصنيعها

Invention

Problem

Conventional bismuth oxyhalide synthesis often uses hydrothermal or solvothermal heating and lengthy processing, while quantum-dot production also requires control of size, morphology, and optical properties.

Why it matters

Simpler quantum-dot synthesis can expand materials research in visible-light photocatalysis, sensing, solar-energy conversion, and other nanomaterial devices while reducing reliance on high-temperature reaction steps.

Approach

The one-pot route forms bismuth oxyhalide quantum dots by combining bismuth-salt and alkali-halide solutions with an aqueous surfactant at about room temperature, followed by filtration. Surfactant selection and concentration help control the resulting nanoscale material.

Who may benefit

Potential beneficiaries include photocatalysis researchers, nanomaterial producers, sensor developers, solar-material laboratories, and water-treatment technology teams.

Potential value

The disclosed method shortens the reaction sequence, operates the synthesis mixture near room temperature, and yields bismuth oxyhalide nanostructures with specified size, surface-area, bandgap, and composition ranges.

Background

Quantum dots offer size-dependent electronic and optical behavior, but their performance depends strongly on reproducible control of crystallinity, morphology, and surface characteristics. Bismuth oxyiodide has a relatively low bandgap within the bismuth oxyhalide family and is investigated for visible-light photocatalysis, sensors, and solar-energy uses. Conventional preparation frequently employs autoclaves, microwave heating, reflux, or other time-consuming thermal treatments. The publication therefore focuses on a short, surfactant-assisted synthesis carried out near room temperature.

Technology overview

A bismuth salt is dissolved in an organic solvent and an alkali-metal halide is dissolved in water. After combining these solutions, the mixture is introduced into an aqueous nonionic-surfactant solution and stirred at 15–25 °C before vacuum filtration. After processing, the claimed products include bismuth oxyhalide quantum dots or nanosheets with defined Bi:I ratio, crystal size, surface area, and bandgap ranges.

Potential applications

Visible-light photocatalyst materials for further water-pollutant degradation studies.
Quantum-dot components for optical or chemical sensing research.
Semiconductor nanomaterials for solar-energy and photoelectrochemical studies.
Bismuth oxyhalide nanostructures for broader nanomaterial-device development.

Evidence-supported advantages

The synthesis reaction is performed near room temperature without an added-heat reaction stage.
A one-pot sequence combines solution formation, surfactant treatment, and filtration.
The claims define short stirring intervals for both the precursor and final mixtures.
Surfactant choice and amount provide variables for controlling morphology and surface characteristics.
The resulting material is described with defined crystal-size, surface-area, bandgap, and Bi:I ranges.

Development stage

Laboratory synthesis and materials characterization, including microscopy and optical measurements, are described; commercialization was not established.

Commercial opportunity

The process may interest photocatalyst, sensor, and nanomaterial manufacturers seeking lower-temperature synthesis routes. Commercial development should verify batch reproducibility, precursor and surfactant handling, post-processing energy, photocatalytic performance, product safety, and scale-up of particle-size control. Cost and yield benchmarks would also be needed.

Patent classifications

WIPO IPC

C09K11/74Materials for applications not otherwise provided for; applications of materials not otherwise provided for
C01G29/00Compounds containing metals not covered by subclasses C01D or C01F

CPC

C01G29/00Compounds containing metals not covered by subclasses C01D or C01F
C09K11/7428Materials for applications not otherwise provided for; applications of materials not otherwise provided for

Inventors

First inventorBabiker Y. Abdulkhair
InventorFaisal K. Algethami
InventorMohamed R. Elamin

Keywords

bismuth oxyhalide
quantum dots
bismuth oxyiodide
room-temperature synthesis
surfactant
photocatalysis
bandgap
nanosheets

Patent document and drawings

The patent publication is mapped to this record. Patent drawings remain within that publication; no separately cleared public media package has been supplied.