He successfully defended his dissertation in June and graduated on Dec. 20. He already has his name on a scientific patent.
Now 23, he says he's still getting used to being called "Dr. Hayes."
"I tell people, 'I'm just Jalaal,' " Hayes said. "They say, 'No, you've earned it.' "
Hayes talked about his accomplishment recently at a Dunkin' Donuts near his new job - teaching anatomy and physiology at Universal Audenried Charter High School. There, he hears "Dr. Hayes" five days a week.
In a way, Hayes has been teaching since he was 9. That's when he began tutoring older students.
"I want to make STEM [science, technology, engineering, and math] easy" and accessible, Hayes said.
His goal is to encourage minority students to pursue STEM careers and to start a campus that is equal parts laboratory and school.
He already has a tutoring company, and accolades from those who see him as a role model.
"For his age and given the percentage of those who earn a Ph.D. in the STEM field who are black or African American, it's quite an accomplishment," said Rachel Upton, of the American Institutes for Research in Washington, who has studied the role of historically black colleges in producing STEM Ph.D.s.
Those schools produce a disproportionately high number, but blacks are still underrepresented in the fields.
Of the 5,061 U.S. citizens or permanent residents who earned doctorates in the physical sciences in 2014, 178, or 3.5 percent, were black or African American, according to the National Science Foundation.
Hayes hopes to help change the numbers.
He grew up within blocks of Temple University. The son of two librarians, Hayes and his three siblings were surrounded by books in nearly every room. The family traveled annually to library conventions.
Hayes "assembled stuff, and read everything," said his father, Tracey, a dean of library services at at the University of Maryland Eastern Shore in Princess Anne. Jalaal Hayes' mother, Kathleen, is a librarian at South Philadelphia High School.
As a youngster, Jalaal Hayes applied what he learned. He advised his father not to use dish detergent with phosphates and demonstrated the principle of sound with a disassembled ink pen, string, and a paper cup.
He became fascinated with chemistry as a 10th-grader at Carver High School of Engineering and Science in North Philadelphia, when he failed to get an A in the subject during one marking period.
From there, Hayes began reading about scientists such as Jesse Ernest Wilkins Jr., who at 13 was the youngest student to enter the University of Chicago and later contributed to the Manhattan Project.
Hayes was inspired and hooked.
By his sophomore year, Hayes said, he had accumulated nearly enough credits in STEM classes to graduate. He later transferred to Northeast Preparatory School in Philadelphia, believing that it would sharpen his study skills in preparation for college. He graduated in 2008.
He won a scholarship to Lincoln University, his parents' alma mater, where he was three years younger than the typical freshman. He was considered "the baby on campus" and his classmates became his protectors.
"I had fun. I just didn't partake in a lot of the activities that college people do," Hayes said.
He earned bachelor's degrees in general science and history.
He enrolled in Delaware State's doctoral program after he met professor Andrew Goudy and learned of his research on hydrogen storage, part of the scientific exploration of clean energy.
Hayes became part of Goudy's research team, and his education was paid for by money from the team's grant awards.
At Delaware State, Hayes was again the young guy protected by his classmates.
While studying for his degree, Hayes presented papers at conferences, including meetings in Italy and England. He was part of a Goudy team that was granted a patent for a new material that can store hydrogen, and he made the finding the topic of his dissertation.
Hayes attributes his accomplishments to hard work more than natural gifts.
"I want to show that, yes, I did this journey," Hayes said, "and, you can do it, too."
Hayes does not have to look too far to prove that theory. In the spring, his brother, Kamal, is scheduled to collect his high school diploma.
He is 15.