A nano-thin Bi.sub.xO.sub.ySe.sub.z low-temperature oxygen transporter membrane for oxygen transport, separation, and two-dimensional (2D) material manipulation comprising a material comprising a compound of Bi.sub.xO.sub.ySe.sub.z and R3m bismuth oxide (Bi.sub.2O.sub.3). A method of making a nano-thin Bi.sub.xO.sub.ySe.sub.z low-temperature oxygen transporter membrane for oxygen transport, separation, and two-dimensional (2D) material manipulation comprising providing an oxygen environment, providing Bi.sub.2Se.sub.3, processing the Bi.sub.2Se.sub.3 in the oxygen environment, incorporating oxygen, removing selenium, creating a structural change, and creating a compound of Bi.sub.xO.sub.ySe.sub.z and R3m bismuth oxide (Bi.sub.2O.sub.3), wherein the material transports oxygen at room temperature.

A nano-thin Bi.sub.xO.sub.ySe.sub.z low-temperature oxygen transporter membrane for oxygen transport, separation, and two-dimensional (2D) material manipulation comprising a material comprising a compound of Bi.sub.xO.sub.ySe.sub.z and R3m bismuth oxide (Bi.sub.2O.sub.3). A method of making a nano-thin Bi.sub.xO.sub.ySe.sub.z low-temperature oxygen transporter membrane for oxygen transport, separation, and two-dimensional (2D) material manipulation comprising providing an oxygen environment, providing Bi.sub.2Se.sub.3, processing the Bi.sub.2Se.sub.3 in the oxygen environment, incorporating oxygen, removing selenium, creating a structural change, and creating a compound of Bi.sub.xO.sub.ySe.sub.z and R3m bismuth oxide (Bi.sub.2O.sub.3), wherein the material transports oxygen at room temperature.

The present disclosure provides a thermoelectric conversion material having a composition represented by a chemical formula of Ba.sub.1-a-b-cSr.sub.bCa.sub.cK.sub.aMg.sub.2Bi.sub.2-dSb.sub.d. In the chemical formula, the following relationships are satisfied: 0.002≤a≤0.1, 0≤b, 0≤c, a+b+c≤1, and 0≤d≤2. In addition, the thermoelectric conversion material has a La.sub.2O.sub.3-type crystal structure.

A preparation method of indium oxide with stable morphology includes: (1) mixing indium oxide powder and bismuth oxide powder according to a mass ratio of 1:0.1-0.5 to obtain a powder mixture; (2) putting the powder mixture into a ball mill for ball milling at room temperature to obtain a uniform powder mixture; (3) putting the obtained uniform powder mixture into a muffle furnace and calcining at 700-1000° C.; and (4) obtaining the indium oxide with cubic stable morphology after the muffle furnace naturally cools to room temperature. The method has advantages of simple synthesis process, short synthesis period, high sample yield, no need of complicated equipment, and morphology of the obtained indium oxide can be maintained after being heated at a high temperature within 1000° C. for 2 hours. An electrochemical sensor prepared by using the indium oxide obtained by the method has better selectivity to nonane.

The invention provides a process for the preparation of bismuth oxyhalide, comprising a precipitation of bismuth oxyhalide in an acidic aqueous medium in the presence of a reducing agent. Also provided are bismuth oxyhalide compounds doped with elemental bismuth Bi.sup.(0). The use of Bi.sup.(0)doped-bismuth oxyhalide as photocatalysts in water purification is also described.

The invention provides a process for the preparation of bismuth oxyhalide, comprising a precipitation of bismuth oxyhalide in an acidic aqueous medium in the presence of a reducing agent. Also provided are bismuth oxyhalide compounds doped with elemental bismuth Bi.sup.(0). The use of Bi.sup.(0)doped-bismuth oxyhalide as photocatalysts in water purification is also described.

The present disclosure generally relates to compositions comprising substrate-free crystalline 2D bismuthene, and the method of making and using the substrate-free crystalline 2D bismuthene.

The present disclosure generally relates to compositions comprising substrate-free crystalline 2D bismuthene, and the method of making and using the substrate-free crystalline 2D bismuthene.

Provided is room temperature stable δ-phase Bi.sub.2O.sub.3. Ion conductive compositions comprise at least 95 wt % δ-phase Bi.sub.2O.sub.3, and, at 25° C., the compositions are stable and have a conductivity of at least 10.sup.−7 S/cm. Related methods, electrochemical cells, and devices are also disclosed.

Provided is room temperature stable δ-phase Bi.sub.2O.sub.3. Ion conductive compositions comprise at least 95 wt % δ-phase Bi.sub.2O.sub.3, and, at 25° C., the compositions are stable and have a conductivity of at least 10.sup.−7 S/cm. Related methods, electrochemical cells, and devices are also disclosed.