High Throughput Screening Of Polymetallic Sulfide/GO Composite Visible Light Catalysts

Hydrogen energy is recognized as a clean energy,due to its advantages of non-toxic harmless,easy storage and transportation.It is considered as an effective strategy to solve the energy crisis and environmental pollution problems.Compared with the traditional hydrogen production technology,photo catalytic hydrogen production technology is more clean,efficient,energy saving.Therefore,the photo catalytic hydrogen production technology has become a hot spot in the field of new energy research.Efficient photo catalysts for the discovery of hydrogen production at low cost have become a huge challenge in the field of materials science,attracting more and more researchers.However,most of the traditional photo catalyst components have a small absorption wavelength range,which makes the utilization of solar energy in the catalytic reaction process is very low and low catalytic activity,to a great extent limit the efficiency of light cracking water hydrogen production,making this technology cannot be widely used.The combination of multi-component photo catalyst synthesis and screening has become a popular task in the field of materials science and new energy,multi-component composite photo catalyst capability to overcome the shortcomings of a single catalyst,greatly improving the catalytic efficiency and solar energy utilization.Based on the above discussion,this research focus on preparing and synthesizing four kinds of catalyst libraries composed of metal sulfide modified grapheme composites MSx/GO(M for different metals),and screen out high-performance catalysts via high-throughput screening method under visible light irradiation.And then calculate the ratio of the three kinds of metal sulfides in the composite catalysts.The main contents and the results are as follows:(1)Preparation of the reaction chip.First,we selected clean glass(size:75 × 25 ×1mm3)as the substrate of the reaction chip,1250(25 × 50)independent hydrophobic cells(1 × 1mm)were successfully constructed on the surface by direct printing method.Next,the GO dispersion was uniformly introduced into the cell of the reaction chip by the spray method.Finally,using a high-resolution inkjet printing technique,0.3 M metal salt solution was printed on the chip surface according to the print template.Last,(MSx/GO)composite catalyst libraries were prepared by the process of sulfide and sintering of gas bath theorem.The catalyst libraries were Ni-Cd-Zn Sx/GO,(Mn-Zn-Ni)Sx/GO,(Ni-Cd-Co)Sx/GO,Cd-Mn-Zn)Sx/GO,respectively.The prepared reaction chips and catalysts were characterized by SEM and TEM.The results show that the reaction chip and catalyst prepared by the above method can meet the requirements of the experiment.(2)We designed and developed a high throughput screening system in order to preform hydrogen production reaction and test the photo catalytic performance of the catalyst.The high-throughput screening system consists of grooved reactor and bubble detection system.The grooved reactor is composed of a glass base,the chip-3,silicone strips and a quartz glass,forming a groove structure to prevent the movement of the bubbles during the photo catalytic reaction.The bubble detection system is composed of a LED light,a digital CCD camera and a computer.The main principle of the bubble detection system is bubble imaging technology,which can photograph the imagines and convert it into digital image.(3)The photo catalytic reaction was performed under 465 nm blue visible light,with 0.25 M Na2SO3 and 0.35 M Na2S as sacrificial agent.The experimental results show that the photocatalysts in the prepared four composite catalyst libraries can response to blue visible light.(4)Image processing software was used to analyze the bubble images.The high-performance catalysts in four catalyst libraries were selected and proportion of its metal elements were calculated according to the bubble total volume of each reaction units.The high-performance catalyst in each catalyst libraries are No.194(No.1 catalyst library),No.196(No.2 catalyst library),No.162(No.3 catalyst library)and No.213(No.4 catalyst library),respectively.The corresponding ratios of these catalysts are Cd0.22Zn0.52Ni0.26Sx/GO,Cd0.25Co0.45Ni0.30Sx/GO,Mn0.42Zn0.50Ni0.08Sx/GO and Cd0.18Zn0.42Mn0.39Sx/GO,respectively.(5)Parallel and blank group experiments were carried out.The results showed that the catalysts prepared in this experiment are stable and the screening method is reproducible.The reaction conditions must satisfy the conditions of light,catalyst and sacrificial agent simultaneously.