For the first time, it is demonstrated that the robust organic semiconductor g-C3N4 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, BiVO4 and WO3. 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 H2 and O2 evolution rate at 36 and 18 μmol h(-1) g(-1) from water over 14 h. Our findings demonstrate g-C3N4 can serve as a multifunctional robust photocatalyst, which could also be used in other systems such as PEC cells or coupled solar cell systems.
We employed transient absorption
spectroscopy (TAS) to investigate
the kinetic dependences of photocatalysis in anatase and rutile TiO2 films of varying morphology. In mesoporous films, anatase
was ∼30 times more efficient than rutile in the photocatalytic
degradation of an intelligent ink model system. Independent of phase,
up to 100 lower levels of photocatalysis were found in dense films.
Charge carrier lifetimes were probed by TAS on the microsecond to
second time scale. For both rutile and anatase, recombination was
independent of morphology. Rutile exhibited up to 10 times slower
recombination kinetics than anatase. Efficient, irreversible hole
scavenging by alcohols was present in mesoporous anatase alone, resulting
in the generation of long-lived electrons (τ ≈ 0.7 s)
which, upon the addition of the dye reduction target resazurin, enabled
efficient electron transfer (τ ≈ 3 ms). Hole scavenging
by alcohols on mesoporous rutile was substantially less efficient
and more reversible than anatase, resulting in only a marginal increase
in electron lifetime. The lower activity of rutile was not due to
differences in recombination but rather to the deficiency of rutile
holes to drive efficient and irreversible alcohol oxidation.
Few chemotherapeutics have had such an impact on cancer management as cis-diamminedichloridoplatinum(II) (CDDP), also known as cisplatin. The first member of the platinum-based drug family, CDDP's potent toxicity in disrupting DNA replication has led to its widespread use in multidrug therapies, with particular benefit in patients with testicular cancers. However, CDDP also produces significant side effects that limit the maximum systemic dose. Various strategies have been developed to address this challenge including encapsulation within micro- or nanocarriers and the use of external stimuli such as ultrasound to promote uptake and release. The aim of this review is to look at these strategies and recent scientific and clinical developments.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.