3 research outputs found
Visible Light-Driven Pure Water Splitting by a Nature-Inspired Organic Semiconductor-Based System
For the first time, it is demonstrated
that the robust organic
semiconductor g-C<sub>3</sub>N<sub>4</sub> can be integrated into
a nature-inspired water splitting system, analogous to PSII and PSI
in natural photosynthesis. Two parallel systems have been developed
for overall water splitting under visible light involving graphitic
carbon nitride with two different metal oxides, BiVO<sub>4</sub> and
WO<sub>3</sub>. Consequently, both hydrogen and oxygen can be evolved
in an ideal ratio of 2:1, and evolution rates in both systems have
been found to be dependent on pH, redox mediator concentration, and
mass ratio between the two photocatalysts, leading to a stable and
reproducible H<sub>2</sub> and O<sub>2</sub> evolution rate at 36
and 18 μmol h<sup>–1</sup> g<sup>–1</sup> from
water over 14 h. Our findings demonstrate g-C<sub>3</sub>N<sub>4</sub> can serve as a multifunctional robust photocatalyst, which could
also be used in other systems such as PEC cells or coupled solar cell
systems
Phase-Tunable Calcium Phosphate Biomaterials Synthesis and Application in Protein Delivery
Calcium phosphates (CaP) are important
biomaterials used in tissue
engineering and drug delivery, due to their biocompatibility, low
toxicity, and osteoconductivity. However, controlling the phase of
CaP, especially tricalcium phosphate (TCP), is very challenging under
mild conditions, particularly when using one preparation protocol
for all CaP phases. It is also crucial to produce these biomaterials
economically and reproducibly. Herein, three of the most commonly
employed CaP, including beta-tricalcium phosphate (β-TCP), dicalcium
phosphate anhydrous (DCPA), and hydroxyapatite (HA) were, for the
first time, successfully synthesized by altering the reaction solvent,
using calcium acetate monohydrate as a precursor and a rapid microwave-assisted
synthetic method. A variety of CaP particle morphologies were obtained,
including elliptical and plate-shaped with different porosities. Compared
with conventional heating, CaP biomaterials synthesized using microwave
heating showed greater reproducibility, higher yields, and shorter
reaction time. By varying the reaction solvents, morphologies and
phases of CaP were controlled, leading to an enhanced protein bovine
serum albumin (BSA) loading, with a higher BSA absorption observed
according to the trend DCPA> β-TCP > HA. Furthermore,
the phase,
specific surface area, and pore size were shown to play decisive roles
in protein desorption with a higher release amount observed according
to the trend DCPA > β-TCP > HA. Finally, it is found that
larger
pores are also beneficial to BSA adsorption
Organosilica Nanoparticles with an Intrinsic Secondary Amine: An Efficient and Reusable Adsorbent for Dyes
Nanomaterials are
promising tools in water remediation because of their large surface
area and unique properties compared to bulky materials. We synthesized
an organosilica nanoparticle (OSNP) and tuned its composition for
anionic dye removal. The adsorption mechanisms are electrostatic attraction
and hydrogen bonding between the amine on OSNP and the dye, and the
surface charge of the OSNP can be tuned to adsorb either anionic or
cationic dyes. Using phenol red as a model dye, we studied the effect
of the amine group, pH, ionic strength, time, dye concentration, and
nanomaterial mass on the adsorption. The theoretical maximum adsorption
capacity was calculated to be 175.44 mg/g (0.47 mmol/g), which is
higher than 67 out of 77 reported adsorbents. The experimental maximum
adsorption capacity is around 201 mg/g (0.53 mmol/g). Furthermore,
the nanoparticles are highly reusable and show stable dye removal
and recovery efficiency over at least 10 cycles. In summary, the novel
adsorbent system derived from the intrinsic amine group within the
frame of OSNP are reusable and tunable for anionic or cationic dyes
with high adsorption capacity and fast adsorption. These materials
may also have utility in drug delivery or as a carrier for imaging
agents