Synthesis and Photocatalytic Performance of ZnO/Bone Char Composite

A comprehensive review of bone char: Fabrication procedures, physicochemical properties, and environmental application

Bone waste from slaughtering is an abundant but underutilized resource. Promoting its exploitation can reduce the environmental burden and achieve energy recovery. Bone char, a solid material prepared by the thermochemical conversion of animal bone, has a unique and rich mesoporous structure and ionic polarity sites. It has shown great potential for application. This review aims to provide information about the thermochemical conversion method of recycling waste bone to fabricate bone char and, on its basis, to summarize comprehensive data on the physicochemical properties to provide direction and theoretical support for the tailored environmental remediation applications. Therefore, the authors first elucidated the various influencing effects (e.g., bone type, pyrolysis atmosphere and temperature, etc.) and modification treatments (physical and chemical methods) during the fabrication of bone char. Secondly, the physicochemical properties (including but not limited to pore structure, elemental composition, surface functional groups, pH and ash content, etc.) of bone char are comprehensively discussed for the first time. Further, the development process of bone char applied as adsorbents and catalytic supports for environmental remediation (decolorization of sugar liquor, drinking water defluoridation, removal of heavy metals and organic pollutants) is presented, revealing the behaviors and mechanisms of pollutant removal by bone char. Finally, the authors present the prospects and challenges of developing bone char into a green and sustainable environmentally friendly material.

Value-added materials recovered from waste bone biomass: technologies and applications

As the world population increases, the generation of waste bones will multiply exponentially, increasing landfill usage and posing health risks. This review aims to shed light on technologies for recovering valuable materials (e.g., alkaline earth material oxide such as CaO, hydroxyapatite, beta tri-calcium phosphate, phosphate and bone char) from waste bones, and discuss their potential applications as an adsorbent, catalyst and catalyst support, hydroxyapatite for tissue engineering, electrodes for energy storage, and phosphate source for soil remediation. Waste bone derived hydroxyapatite and bone char have found applications as a catalyst or catalyst support in organic synthesis, selective oxidation, biodiesel production, hydrocracking of heavy oil, selective hydrogenation and synthesis of bioactive compounds. With the help of this study, researchers can gather comprehensive data on studies regarding the recycling of waste bones, which will help them identify material recovery technologies and their applications in a single document. Furthermore, this work identifies areas for further research and development as well as areas for scaling-up, which will lead to reduced manufacturing costs and environmental impact. The idea behind this is to promote a sustainable environment and a circular economy concept in which waste bones are used as raw materials to produce new materials or for energy recovery.

Facile preparation of a cobalt diamine diketonate adduct as a potential vapor phase precursor for Co3O4films

Co3O4 thin films and nanosystems are implemented in a broad range of functional systems, including gas sensors, (photo)catalysts, and electrochemical devices for energy applications. In this regard, chemical vapor deposition (CVD) is a promising route for the fabrication of high-quality films in which the precursor choice plays a key role in the process development. In this work, a heteroleptic cobalt complex bearing fluorinated diketonate ligands along with a diamine moiety [Co(tfa)2·TMEDA; tfa = 1,1,1-trifluoro-2,4-pentanedionate and TMEDA = N,N,N',N'-tetramethylethylenediamine] is investigated as a potential Co molecular precursor for the CVD of Co3O4 systems. For the first time, the compound is characterized by crystal structure determination and comprehensive analytical studies, focusing also on its thermal properties and fragmentation patterns, important figures of merit for a CVD precursor. The outcomes of this investigation, accompanied by detailed theoretical studies, highlight its very favorable properties for CVD applications. In fact, growth experiments under oxygen atmospheres containing water vapor revealed the suitability of Co(tfa)2·TMEDA for the fabrication of high-quality, phase-pure Co3O4 thin films. The versatility of the proposed strategy in tailoring Co3O4 structural/morphological features highlights its potential to obtain multi-functional films with controllable properties for a variety of eventual technological end-uses.