Wenyue Su

Photocatalytic and Antibacterial Properties of Medical-Grade PVC Material Coated With TiO2 Film

The TiO(2) film was coated on poly vinyl chloride (PVC) surface by dip-coating process from TiO(2)-PVC-THF suspension. The morphology and crystal structure of the as-synthesized samples were characterized by SEM and XRD. The photocatalytic properties were measured by the photodegradation reaction of RhB and the anti-adhesion and anti-bacteria for Escherichia coli. The results show that the resultant TiO(2) film is well-conglutinated on PVC surface and has the same crystal structure as the original TiO(2) powder. The TiO(2)/PVC shows excellent photocatalytic activity for the degradation of aqueous RhB and the activity increases with increasing reaction time and tends toward stable after accumulative illumination for 11.5 h. The TiO(2) film shows good bacterial anti-adhesion activity following photo-activation and sterilization property under UV irradiation. The E. coli can be killed completely after UV irradiation for 1.5 h.

Self-assembly synthesis of LaPO4 hierarchical hollow spheres with enhanced photocatalytic CO2-reduction performance

Urchin-like LaPO4 hollow spheres were successfully synthesized by a facile solution route using citric acid (CA) as a structure-directing agent. The size of the three-dimensional (3D) hollow spheres was tuned by changing the concentration of CA. The formation mechanism of the 3D LaPO4 hollow spheres was revealed by studying the time-dependent morphology evolution process. Importantly, compared with monodispersed one-dimensional (1D) LaPO4 nanorods, the 3D LaPO4 hollow spheres self-assembled from nanorods showed a 6.8-fold enhancement in photocatalytic activity for CO2 reduction, which is attributed to the synergistic effect of their hierarchical hollow structure, higher light-harvesting capacity, and faster electron transfer. Our findings provide not only a simple, facile method for the synthesis of hierarchical hollow micro/nanoarchitectures but also an efficient route for enhancing the photocatalytic performance.

Enhanced photocatalytic CO2 conversion over LaPO4 by introduction of CoCl2 as a hole mediator

The photocatalytic CO2 reduction over LaPO4 was significantly enhanced by simply introducing CoCl2 into the aqueous medium. The introduced CoCl2 functioned as a co-catalyst accelerating photogenerated hole transfer, by the reversible redox couple CoIII–Cl/CoII–Cl, effectively suppressing the recombination of photogenerated charges.

La2Sn2O7 enhanced photocatalytic CO2 reduction with H2O by deposition of Au co-catalyst

La2Sn2O7 (LSO) micro/nanospheres, synthesized by a hydrothermal method, exhibited photocatalytic performance for CO2 reduction. The evolution rate of the main reduction products (CH4 and CO) was 0.20 and 0.10 μmol h−1, respectively. Loading of Au co-catalyst over La2Sn2O7 efficiently enhanced the photocatalytic activity of CO2 reduction. The highest photocatalytic efficiency was obtained over 1 wt% Au/La2Sn2O7 with an apparent quantum yield (AQY) of 2.54%. Characterization techniques including SEM, TEM, XRD, XPS, DRS, PL, and electrochemical analysis were applied and the physicochemical properties of La2Sn2O7 and Au/La2Sn2O7 samples are discussed. A possible mechanism of photocatalytic CO2 reduction over Au/La2Sn2O7 is proposed.

Cobalt lactate complex as a hole cocatalyst for significantly enhanced photocatalytic H2 production activity over CdS nanorods

Photocatalytic water splitting has been widely investigated in recent years, and most of the catalysts depend strongly on noble metal co-catalysts which are scarce and expensive. Herein, we report a noble metal free system using CdS nanorods as a photocatalyst and a cobalt lactate complex as a cocatalyst. Under visible light irradiation, a H2 evolution rate of 15.59 mmol h−1 g−1 is obtained when the CdS and cobalt lactate complex are used for photocatalytic water splitting; this rate is 3 times that obtained with a Pt/CdS photocatalyst. Moreover, the stability of CdS is also obviously improved using a cobalt lactate complex as a cocatalyst. The origin of the improved photoactivity is investigated by a variety of controlled experiments. The results show that the cobalt lactate complex as a hole acceptor inhibits the recombination of photo-generated electrons and holes.

An amorphous CoSx modified Mn0.5Cd0.5S solid solution with enhanced visible-light photocatalytic H2-production activity

It is of significant importance to develop cheap and efficient co-catalysts for photocatalytic H2 production. Herein, a series of highly efficient and noble metal-free CoSx modified Mn0.5Cd0.5S nanocomposites are successfully synthesized via a simple direct precipitation process. The photocatalytic activity of the as-prepared photocatalysts for H2 production from water splitting under visible-light irradiation is investigated. It can be found that the rate of H2 evolution over CoSx/Mn0.5Cd0.5S is 2.4 times higher than that of pure Mn0.5Cd0.5S, which is comparable to Mn0.5Cd0.5S modified with 1 wt% platinum (Pt) co-catalyst. The products are systematically characterized by XRD, UV-vis DRS, SEM, TEM, HRTEM, XPS, PL and so on. According to the above experimental results, it can be concluded that the amorphous CoSx nanoparticles function as active sites and excellent electron transfer mediators for the catalytic reaction.