The Research Of Novel Noble-metal-free Phosphide As Cocatalyst For Photocatalytic Hydrogen Production

Energy crisis and environmental pollution have been a significant challenge for China and even global facing.Achieving hydrogen energy by solar photocatalytic splitting water is an efficient approach to resolve the energy crisis and environmental pollution.The photogenerated electron-hole pairs cannot separate from each other efficiently because there are no enough active sites on the surface of pure photocatalyst.So the photocatalytic hydrogen production activity is very low.Loading noble metal cocatalyst on the surface of photocatalyst can promote the separation of photogenerated electron-hole pairs and increase the amount of active sites,so the photocatalytic hydrogen production activity improves highly.However,the rare resources and high cost inhibit the wide application of noble metal cocatalyst.This research tries to develop the research of noble metal free phosphide cocatalyst.Several high active noble metal free phosphide cocatalyst were screened by experiments,such as WP,Fe_xCo_1-xP,NiCoP and so on.These cocatalysts improved the activity and stability of photocatalytic splitting water to achieve hydrogen efficiently.The results mainly achieved in the research are as followed:?1?WP nanoparticles were synthesized via a simple wet chemical process.The synthesized WP cocatalyst nanoparticles were loaded on the surface of commercial CdS by ball-milled to form the WP/CdS compound photocatalyst as followed.WP/CdS compound photocatalyst synthesized showed high efficient activity of photocatalytic splitting water to achieve hydrogen under visible light irradiation.It was found the activity of photocatalytic splitting water to achieve hydrogen can achieve highest value when the 4.0 wt.%WP nanoparticles were loaded on the surface of CdS.The highest activity was about 11.67 times than that of pure CdS.The electrochemical analysis indicated that WP had high activity of electrocatalytic splitting water to achieve hydrogen and there was efficient charge transfer between the interfaces of WP/CdS compound materials.These results confirmed WP is an excellent cocatalyst for photocatalytic hydrogen production.The activity of photocatalytic splitting water of CdS to achieve hydrogen improved efficiently after WP loaded on the surface of CdS.?2?Ternary Fe_xCo_1-xP nanoparticles were synthesized with the method of chemical coprecipitation.The synthesized Fe_xCo_1-xP nanoparticles were loaded on the surface of commercial CdS to form Fe_xCo_1-xP/CdS compound photocatalyst by the means of mechanical stirring.The synthesized Fe_xCo_1-xP/CdS compound photocatalyst showed high activity of photocatalytic splitting water to achieve hydrogen under visible light irradiation.It was found the activity of photocatalytic splitting water to achieve hydrogen was up to highest when the molar rate of Fe and Co was 4:6.The highest activity was about 5.85 times than that of pure CdS and about 75.8%than that of Pt/CdS.The electrochemical analysis of Fe_xCo_1-xP nanoparticles indicated Fe_xCo_1-xP had high activity of electrocatalytic splitting water to achieve hydrogen and there was efficient charge transfer between the interfaces of Fe_xCo_1-xP/CdS compound materials.These results confirmed the ternary Fe_xCo_1-xP nanoparticle was a high efficient and stable cocatalyst for photocatalytic hydrogen production.The activity of photocatalytic splitting water to achieve hydrogen improved efficiently after Fe_xCo_1-xP loaded on the surface of photocatalyst.?3?Ternary NiCoP nanoparticles were synthesized with one step of hydrothermal method.The synthesized NiCoP nanoparticles were loaded on the surface of commercial CdS to form NiCoP/CdS compound photocatalyst by the means of evaporation in the ethanol.The NiCoP/CdS compound photocatalyst after ultrasonic exfoliation showed high efficient photocatalytic splitting water to achieve hydrogen under visible light irradiation.It was found the activity of photocatalytic splitting water of NiCoP/CdS to achieve hydrogen after ultrasonic exfoliation was 1.62times than that of NiCoP/CdS before ultrasonic exfoliation,about 10.86times than that of pure CdS and was even up to 96%than that of Pt/CdS.The electrochemical analysis of NiCoP nanoparticles indicated that NiCoP owned high efficient activity of electrocatalytic splitting water to achieve hydrogen and there was efficient charge transfer between the interfaces of NiCoP/CdS compound materials.These results confirmed the ternary NiCoP nanoparticle was a high efficient and stable cocatalyst which couble be a substitution of noble metal Pt for photocatalytic hydrogen production.The activity of photocatalytic splitting water to achieve hydrogen improved highly after NiCoP loaded on the surface of CdS.