Visible-Light Activation of Photocatalytic for Reduction of Nitrogen to Ammonia by Introducing Impurity Defect Levels into Nanocrystalline Diamond

Abstract

Nitrogen impurity has been introduced in diamond film to produce a nitrogen vacancy center (NV center) toward the solvated electron-initiated reduction of N2 to NH3 in liquids, giving rise to extend the wavelength region beyond the diamond’s band. Scanning electron microscopy and X-ray diffraction demonstrate the formation of the nanocrystalline nitrogen-doped diamond with an average diameter of ten nanometers. Raman spectroscopy and PhotoLuminescence (PL) spectrum show characteristics of the NV0 and NV− charge states. Measurements of photocatalytic activity using supraband (λ < 225 nm) gap and sub-band gap (λ > 225 nm) excitation show the nitrogen-doped diamond significantly enhanced the ability to reduce N2 to NH3 compared to the polycrystalline diamond and single crystal diamond (SCD). Our results suggest an important process of internal photoemission, in which electrons are excited from negative charge states into conduction band edges, presenting remarkable photoinitiated electrons under ultraviolet and visible light. Other factors, including transitions between defect levels and processes of reaction, are also discussed. This approach can be especially advantageous to such as N2 and CO2 that bind only weakly to most surfaces and high energy conditions.

Degradation of Perfluorooctanoic Acid with Hydrated Electron by a Heterogeneous Catalytic System

“…Consequently, the energy of photon is high enough that could excite diamond catalyst to pump electron to surrounding environment, making diamond a solid-catalyst electron source . Electron emission is not limited to a vacuum; rather, electrons could also emit into aqueous phase with a negligible barrier. , In this regard, new pathways emerge to emit electrons into surrounding water phase rather than to the surface of the semiconductor, that is, the NEA allows electronsextremely potent reducing agentsto transfer directly into a reactant solution. Thus, diamond is believed to be an alternative heterogeneous catalyst in ARP systems to produce energetic e aq – , which could decompose refractory pollutants effectively.…”

A minireview on catalysts for photocatalytic N2 fixation to synthesize ammonia

“…Ammonia (NH 3 ) is one of the basic raw materials in industrial chemistry and has been widely applied in various elds. [1][2][3][4] Industrially, NH 3 could be used to produce fertilizers, synthetic bres, nitrile rubber and so on; medically, NH 3 is oen utilized as a drug to treat dizziness and fainting; militarily, NH 3 could serve as a biological disinfectant to disinfect sarin agents. The wide applications of NH 3 make it essential in promoting the development of national economies.…”

Fabrication of a Micron-Scale Three-Dimensional Single Crystal Diamond Channel Using a Micro-Jet Water-Assisted Laser

“…Diamond with microchannels is an ideal substrate for cooling chip temperatures and achieving low thermal resistance [ 3 , 4 , 5 ]; enlarging surface and heat exchange areas of catalytic elements [ 6 , 7 , 8 , 9 ], and assisting with liquid transport as a stent in medical equipment [ 10 , 11 ]. Due to the wider application of diamond microchannels, the importance of improving microchannel fabrication has increased.…”