title: Sustainable one-pot integration of ZnO nanoparticles into carbon spheres: manipulation of the morphological, optical and electrochemical properties.
abstract: ZnO-carbon composite spheres were synthesized via starch hydrothermal carbonization (HTC) in the presence of a soluble zinc salt (acetate), followed by thermal processing under an argon atmosphere. Besides sustainability, the one-pot procedure represents a scalable synthesis of tailored carbon-metal oxide spheres with a structurally-ordered carbon matrix obtained at a relatively low temperature (700 °C). The ability of zinc cations to develop different linkages with starch's hydrophilic functional groups and to act as external nucleators determines an increase in HTC yield; the effect is obvious even in the presence of small concentrations of zinc in the reaction medium (0.005 M), thus providing a way to improve the carbonization process efficiency. It is also shown that zinc content is the control vector of the spherical composite's properties: a variation from 0.3 to 4.8 at% not only induces a variation in their size (200 nm-10 μm), interconnectivity (from disperse spheres to necklace-like aggregations), surface area and connected porosity (from micro- to mesoporosity), but also of their electrochemical and white light adsorption and emission features. Since the variation in zinc content is made by a simple adjustment of the raw material concentrations, the functionality of these carbon-based materials can be modulated in a straightforward manner.
authors: "Ilie Murgulescu" Institute of Physical Chemistry, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest, Romania. josecalderonmoreno@yahoo.com, tspataru@icf.ro; ocarp@icf.ro.
authors: Greta
authors: G
authors: Patrinoiu
authors: "Ilie Murgulescu" Institute of Physical Chemistry, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest, Romania. josecalderonmoreno@yahoo.com, tspataru@icf.ro; ocarp@icf.ro.
authors: Jose M
authors: JM
authors: Calderon-Moreno
authors: Photonic Processing of Advanced Materials, National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor, PO-Box MG-36, 077125 Bucharest, Romania.
authors: Ruxandra
authors: R
authors: Birjega
authors: "Ilie Murgulescu" Institute of Physical Chemistry, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest, Romania. josecalderonmoreno@yahoo.com, tspataru@icf.ro; ocarp@icf.ro.
authors: Daniela C
authors: DC
authors: Culita
authors: "Ilie Murgulescu" Institute of Physical Chemistry, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest, Romania. josecalderonmoreno@yahoo.com, tspataru@icf.ro; ocarp@icf.ro.
authors: Simona
authors: S
authors: Somacescu
authors: "Ilie Murgulescu" Institute of Physical Chemistry, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest, Romania. josecalderonmoreno@yahoo.com, tspataru@icf.ro; ocarp@icf.ro.
authors: Adina M
authors: AM
authors: Musuc
authors: "Ilie Murgulescu" Institute of Physical Chemistry, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest, Romania. josecalderonmoreno@yahoo.com, tspataru@icf.ro; ocarp@icf.ro.
authors: Tanta
authors: T
authors: Spataru
authors: "Ilie Murgulescu" Institute of Physical Chemistry, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest, Romania. josecalderonmoreno@yahoo.com, tspataru@icf.ro; ocarp@icf.ro.
authors: Oana
authors: O
authors: Carp