CAJ | 학술논문

使用第一性原理研究了C位掺杂的g-C3N4的电学性质和光学性质，掺杂原子为B、P、S. g-C3N4有C1位和C2位两种对称位碳原子，其中在C1位上的掺杂易于C2位，掺杂体系也较C2位稳定.相比于磷和硫在g-C3N4上的掺杂，硼掺杂最易于进行.掺杂后体系的晶体结构之间差别较大，这与掺杂原子的大小以及电负性有关.由轨道布居分布可知，掺杂后的硼、磷、硫原子价电子发生了变化，表明掺杂原子发生了杂化，与相邻原子以强的共价键相连.掺杂原子与被取代的碳原子之间的价电子差异导致了能带的增加.在原来的体系中，掺杂后的体系出现了一条新的能带，因此导致实际带隙下降，表明了掺杂后的体系导电性能增强.对纯g-C3N4及掺杂g-C3N4的光学性质分析表明， g-C3N4的光学吸收主要在紫外光区，掺杂磷和硫后对g-C3N4的光吸收波长范围无改变，掺杂硼后的g-C3N4光吸收不再局限于紫外光区，而且延伸至可见光区和红外光区，并在红外光区有很强的吸收，表明g-C3N4掺杂硼后能大大地提高光催化效率.电子能量损失光谱和光导率谱以及介电常数都佐证了上述观点.
사용제일성원리연구료C위참잡적g-C3N4적전학성질화광학성질，참잡원자위B、P、S. g-C3N4유C1위화C2위량충대칭위탄원자，기중재C1위상적참잡역우C2위，참잡체계야교C2위은정.상비우린화류재g-C3N4상적참잡，붕참잡최역우진행.참잡후체계적정체결구지간차별교대，저여참잡원자적대소이급전부성유관.유궤도포거분포가지，참잡후적붕、린、류원자개전자발생료변화，표명참잡원자발생료잡화，여상린원자이강적공개건상련.참잡원자여피취대적탄원자지간적개전자차이도치료능대적증가.재원래적체계중，참잡후적체계출현료일조신적능대，인차도치실제대극하강，표명료참잡후적체계도전성능증강.대순g-C3N4급참잡g-C3N4적광학성질분석표명， g-C3N4적광학흡수주요재자외광구，참잡린화류후대g-C3N4적광흡수파장범위무개변，참잡붕후적g-C3N4광흡수불재국한우자외광구，이차연신지가견광구화홍외광구，병재홍외광구유흔강적흡수，표명g-C3N4참잡붕후능대대지제고광최화효솔.전자능량손실광보화광도솔보이급개전상수도좌증료상술관점.
Some properties of g-C3N4 with carbon positions doped by B, P, and S atoms were investigated using quantum mechanics (first principles). There are two symmetric carbon atoms in g-C3N4, named C1 and C2. C1 is easier to dope than C2, and the system doped at C1 is more stable. It was found that it is easier to dope g-C3N4 with B than with P and S. There are significant differences among the crystal structures after doping, this is attributed to the sizes and electronegativities of the different doping atoms. The orbital population distributions showed that the electronic valences of the B, P, and S atoms changed when the doping was changed. This shows that hybrid doped atoms linked with adjacent atoms through covalent bonds are present. The differences between the valence electrons of the dopant atoms and the substituted atoms result in new bands after doping. The emergence of a new energy band in the band gap of the original g-C3N4 results in a decreased band gap after doping, indicating that the conductivity of the doped system is higher than that of the non-doped system. Analyses of the optical properties of pure g-C3N4 and doped g-C3N4 show that the optical absorption spectrum of g-C3N4 is mainly in the ultraviolet region, and the wavelength range of light absorption is unchanged after doping with P and S. However, after doping with B, the wavelength range of light absorption extends to the visible and infrared regions. Strong absorption in the infrared region shows that the photocatalytic activity of g-C3N4 after doping with B is much higher than that of undoped g-C3N4. The electron energy loss spectrum, optical conductivity spectrum, and the dielectric function curve support these points.