Degradation of 4-nitrophenol by electrocatalysis and advanced oxidation processes using Co3O4@C anode coupled with simultaneous CO2 reduction via SnO2/CC cathode

Herein,we prepa red novel three-dimensional(3D)gear-s haped Co3O4@C(Co3O4 modified by amorphous carbon)and sheet-like SnO2/CC(SnO2 grow on the carbon cloth)as anode and cathode to achieve efficient removal of 4-nitrophenol(4-NP)in the presence of peroxymonosulfate(PMS)and simultaneous electrocatalytic reduction of CO2,respectively.In this process,4-NP was mineralized into CO2 by the Co3O4@C,and the generated CO2 was reduced into HCOOH by the sheet-like SnO2/CC cathode.Compared with the pure Co0.5(Co3O4 was prepared using 0.5 g urea)with PMS(30 mg,0.5 g/L),the degradation efficiency of 4-NP(60 mL,10 mg/L)increased from 74.5%-85.1%in 60 min using the Co0.5 modified by amorphous carbon(Co0.5@C).Furthermore,when the voltage of 1.0 V was added in the anodic system of Co0.5@C with PMS(30 mg,0.5 g/L),the degradation efficiency of 4-NP increased from 85.1%-99.1%when Pt was used as cathode.In the experiments of 4-NP degradation coupled with simultaneous electrocatalytic CO2 reduction,the degradation efficiency of 4-NP was 99.0%in the anodic system of Co0.5@C with addition of PMS(30 mg,0.5 g/L),while the Faraday efficiency(FE)of HCOOH was 24.1%at voltage of-1.3 V using the SnO2/CC as cathode.The results showed that the anode of Co3O4 modified by amorphous carbon can markedly improve the degradation efficiency of 4-NP,while the cathode of SnO2/CC can greatly improve the FE and selectivity of CO2 reduction to HCOOH and the stability of cathode.Finally,the promotion mechanism was proposed to explain the degradation of organic pollutants and reduction of CO2 into HCOOH in the process of electrocatalysis coupled with advanced oxidation processes(AOPs)and simultaneous CO2 reduction.

Halogenated benzothiadiazole-based conjugated polymers as efficient photocatalysts for dye degradation and oxidative coupling of benzylamines

Donor-acceptor(D-A)conjugated polymers are widely used in photovoltaic applications and heteroge-neous catalysis due to their tunable building block and pre-designable structures.Here,a series of ad-justable Donor-acceptor(D-A)benzothiodiazole-based conjugated polymers were designed and synthe-sized.The photocatalytic performance could be improved by fine-tuning the chemical structure by halo-gen substitution(F or Cl).The polymers exhibited excellent optoelectronic properties and were effective photocatalysts for the degradation of RhB and MO dyes,as well as promoting the oxidative coupling of benzylamines.Complete degradation of RhB and MO occurred in 30 min under visible light radiation,while the yield of benzylamine coupling mediated by superoxide anion was as high as 82%.Systematic characterization methods were used to gain insights on the unique photocatalytic performance of the polymers.Our findings provide further insights into the design and synthesis of benzothiadiazole-based conjugated polymers as promising organic photocatalysts for solar energy conversion.

Effective design of A-D-A small molecules for high performance organic solar cells via F atom substitution and thiophene bridge

Three novel small molecules with acceptor-donor-acceptor(A-D-A) configuration,SBDT1,SBDT2 and SBDT3,where 4,8-bis(octyloxy)benzo[1,2-b:4,5-b’]dithiophene(BDT) as the electron-donating core connecting to thiophene-substituted benzothiadiazole(BT) as electron-withdrawing are reported.The effects of fluorine atoms on the photophysical properties by introducing different fluorine atoms into the benzothiadiazole unit were investigated.These SBDTs exhibit good thermal stability,excellent panchromatic absorption in solution and film.SBDT2 and SBDT3 with fluorine-substituted BT possess a relatively deeper the highest occupied molecular orbital(HOMO).These A-D-A type molecules were treated as donor and PC71 BM as acceptor in bulk heterojunction(BHJ) small-molecule organic solar cells(SMOSCs).Among them,device based on SBDT2 gave the best device performance with a PCE of 5.06%with Jsc of 10.56 mA/cm^2,Voc of 0.85 V,fill factor(FF) of 56.4%.These studies indicate that proper incorporation of fluorine atoms is an effective way to increase the efficiency of organic solar cells.